Signal transmission method, network device, and terminal device

ABSTRACT

Embodiments of the present disclosure provide a signal transmission method, network device, and terminal device. The method includes: determining a first time-frequency resource; obtaining a second time-frequency resource and a third time-frequency resource based on the first time-frequency resource and a preset rule, where the third time-frequency resource includes at least one resource element (RE) at a predefined location in the first time-frequency resource, the second time-frequency resource includes a resource other than the third time-frequency resource in the first time-frequency resource, the preset rule indicates the predefined location, the second time-frequency resource is used to carry a beamformed control channel, and the third time-frequency resource is used to carry a reference signal of the beamformed control channel.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/588,336, filed on Sep. 30, 2019, which is a continuation of U.S.patent application Ser. No. 16/188,829, filed on Nov. 13, 2018 (now U.S.Pat. No. 10,447,354), which is a continuation of InternationalApplication No. PCT/CN2016/082070, filed on May 13, 2016. All of theafore-mentioned patent applications are hereby incorporated by referencein their entireties.

TECHNICAL FIELD

Embodiments of the present disclosure relate to the field ofcommunications technologies, and in particular, to a signal transmissionmethod, network device, and terminal device.

BACKGROUND

In wireless communications, in a scenario of using a low-frequencycarrier, a wireless signal has a relatively small path loss, and a beamformed at each antenna port is a wide beam; and therefore, users of anentire cell can be covered. For example, as shown in FIG. 1, a broadcastchannel, a system message, paging, and the like of a network device maybe transmitted by using a wide beam, to better cover a terminal device 1and a terminal device 2.

However, in a high-frequency scenario, as shown in FIG. 2, a path lossof a wireless signal increases. If a wide beam is still used fortransmission, cell coverage becomes very small and cannot cover arelatively remote terminal device 3 and terminal device 4.

An antenna distance may become smaller in high frequency, so that a unitarea can accommodate more antennas. Therefore, a large antenna gain maybe obtained by using a massive multiple-input multiple-output (massiveMIMO) beamforming technology, to compensate for the path loss. There maybe a large quantity of antennas even hundreds of antennas in massiveMIMO. When a large antenna gain is obtained, a formed beam is verynarrow in width. One narrow beam can cover only a part of an area, butcannot cover all users in a cell. For example, as shown in FIG. 3, abeam B2 can cover only a terminal device 5, but cannot cover a terminaldevice 6.

In a high-frequency multi-beam transmission scenario, to serve the usersin the cell, different beams may need to serve the users in the cell ina time division manner, and the beams need common channels such as abroadcast channel, a synchronization channel, and a control channel tocover all the users in the cell, so that the users in the cell aresynchronized and obtain a necessary system message to access the cell.

A beamformed control channel is sent by using an existing method forsending a control channel. For example, an existing control channel is aphysical downlink control channel (PDCCH), and a beamformed controlchannel is a beamformed PDCCH. In this case, in one subframe, there maybe both the PDCCH with large coverage used to serve an old terminaldevice, and the beamformed PDCCH used to serve a terminal device inenlarged coverage. The PDCCH with wide coverage is demodulated by usinga common reference signal (CRS) with wide coverage. However, thebeamformed PDCCH cannot be demodulated by using the existing CRS, andneeds to be demodulated by using a beamformed reference signal.Therefore, when the beamformed PDCCH is used, a UE cannot correctlyreceive the beamformed PDCCH if there is no corresponding beamformedreference signal.

Therefore, how to transmit a beamformed control channel and a referencesignal of the beamformed control channel becomes a problem that urgentlyneeds to be resolved.

SUMMARY

Embodiments of the present disclosure provide a signal transmissionmethod, network device, and terminal device. In this method, abeamformed control channel and a reference signal of the beamformedcontrol channel can be transmitted.

According to a first aspect, a signal transmission method is provided,and the method includes:

-   -   determining a first time-frequency resource, where the first        time-frequency resource is a first candidate resource in a        plurality of candidate resources;    -   obtaining a second time-frequency resource and a third        time-frequency resource based on the first time-frequency        resource and a preset rule, where the third time-frequency        resource includes at least one resource element RE at a        predefined location in the first time-frequency resource, the        second time-frequency resource includes a resource other than        the third time-frequency resource in the first time-frequency        resource, the preset rule indicates the predefined location, the        second time-frequency resource is used to carry a beamformed        control channel, and the third time-frequency resource is used        to carry a reference signal of the beamformed control channel;        and    -   respectively transmitting the beamformed control channel and the        reference signal of the beamformed control channel to a terminal        device by using the second time-frequency resource and the third        time-frequency resource.

Therefore, in this embodiment of the present disclosure, resourcescarrying the beamformed control channel and the reference signal of thebeamformed control channel are determined, to transmit the beamformedcontrol channel and the reference signal of the beamformed controlchannel. In this way, it becomes possible to improve coverage of acontrol channel through beamforming in an existing system.

In addition, a design of the beamformed control channel and thereference signal used for demodulating the beamformed control channel isused in this embodiment of the present disclosure, to improve coverageand performance of the control channel in comparison with a conventionalcontrol channel, and especially, to improve coverage of a cell using ahigh-frequency carrier. In addition, introduction of the beamformedcontrol channel has no impact on or has slight impact on compatibilityof a conventional terminal device.

It should be noted that the term “candidate resource” according to thisembodiment of the present disclosure is defined as follows:

One time-frequency resource set may be divided into a plurality oftime-frequency resource subsets, and the candidate resource is aresource that includes one or more time-frequency resource subsetsselected based on a specific rule.

For example, in a Long Term Evolution (LTE) system, the time-frequencyresource set may be time-frequency resources corresponding to firstthree orthogonal frequency division multiplexing (OFDM) symbols in asubframe. The time-frequency resource subset may be a control channelelement (CCE) or an enhanced control channel element (ECCE). Thecandidate resource is one or more subsets selected based on the specificrule. For example, the candidate resource includes one CCE, two CCEs,four CCEs, or eight CCEs, and a corresponding aggregation level isrespectively 1, 2, 4, or 8.

For example, a network device may determine the first time-frequencyresource based on an existing method for determining a PDCCH resource inLTE.

Optionally, the determining a first time-frequency resource includes:

-   -   determining an aggregation level, where the aggregation level is        used to indicate a size of the candidate resource; and    -   selecting one candidate resource from a set of the plurality of        candidate resources corresponding to the aggregation level, and        using the candidate resource as the first time-frequency        resource.

Specifically, the network device may first determine the aggregationlevel. The aggregation level is used to indicate the size of thecandidate resource. For example, the network device may first determinea PDCCH format. A PDCCH format corresponds to a specific aggregationlevel, the aggregation level corresponds to a quantity of CCEs carryinga PDCCH, and the quantity of CCEs corresponds to a size of a candidateresource in the PDCCH format.

Then, the candidate resource is selected from the set of the pluralityof candidate resources corresponding to the aggregation level, and thecandidate resource is used as the first time-frequency resource.

It should be understood that the aggregation level may include 4 and 8;1, 2, 4, and 8; or the like. For detailed description of the aggregationlevel, refer to a definition in an existing standard. Details are notdescribed herein.

It should be understood that the first time-frequency resource mayinclude a plurality of (a quantity corresponds to an aggregation level)resource element (RE) sets, and each of the plurality of RE setsincludes a same fixed quantity of REs.

For example, in LTE, an RE set is a control channel element CCE, a PDCCHis carried by at least one CCE, and a quantity of CCEs carrying thePDCCH is determined by an aggregation level. For example, a quantity ofCCEs may be 1, 2, 4, or 8. One CCE includes nine resource element groups(REGs), and one REG includes four REs. In other words, one RE set mayinclude 36 REs. Only LTE is used as an example herein for description.In different systems, one RE set may include another quantity of REs.This embodiment of the present disclosure is not limited thereto.

In the LTE system, the first time-frequency resource may be obtainedthrough respectively aggregating one control channel element CCE, twoconsecutive CCEs, four consecutive CCEs, or eight consecutive CCEs infirst three orthogonal frequency division multiplexing OFDM symbols in asubframe for an aggregation level 1, 2, 4, or 8. For example, as shownin FIG. 5, the first time-frequency resource includes eight CCEs,respectively CCE 0 to CCE 7.

In other words, the candidate resource set herein may correspond to anexisting resource set carrying an existing PDCCH.

In this embodiment of the present disclosure, the first time-frequencyresource may be used to carry a beamformed PDCCH, and may be used tocarry a reference signal of the beamformed PDCCH.

It should be understood that the plurality of candidate resources inthis embodiment of the present disclosure may include candidateresources corresponding to all aggregation levels, or may includecandidate resources corresponding to one aggregation level. This is notlimited in this embodiment of the present disclosure.

It should be understood that the foregoing describes a process ofdetermining the first time-frequency resource based on the existingmethod for determining a PDCCH resource in LTE, and describes an examplein which the first time-frequency resource may include a plurality ofCCEs. In this embodiment of the present disclosure, alternatively, thefirst time-frequency resource may be the first time-frequency resourcethat is determined by the network device based on an existing method fordetermining an enhanced physical downlink control channel (EPDCCH)resource in LTE. The EPDCCH is carried by at least one ECCE. A quantityof ECCEs carrying the EPDCCH is determined based on an EPDCCH format.Each EPDCCH format corresponds to a specific aggregation level, and theaggregation level corresponds to a specific quantity of ECCEs. An EPDCCHcandidate resource set may correspond to a resource set that includes aspecific quantity of ECCEs corresponding to an EPDCCH format. Each ECCEmay include four or eight EREGs. The aggregation level corresponding tothe EPDCCH format includes 1, 2, 4, 8, 16, and 32. In other words, acorresponding first time-frequency resource may include 1, 2, 4, 8, 16,and 32 ECCEs.

It should be understood that the preset rule in this embodiment of thepresent disclosure may be a rule preset in the system. In other words,the preset rule may be a rule on which the network device and theterminal device preagree. After the first resource is determined, thenetwork device and the terminal device may obtain the second resourceand the third resource based on the preset rule.

It should be understood that the preset rule may be a rule on which thenetwork device and the terminal device preagree. After the firstresource is determined, the network device and the terminal device mayobtain the second resource and the third resource based on the presetrule. Alternatively, the preset rule may be notified by the networkdevice to the terminal device by using signaling. To be specific, thenetwork device sends a message in advance to agree on the preset rulewith the terminal device.

Correspondingly, in another embodiment, before 410, the method mayfurther include: sending an indication message to the terminal device,where the indication message indicates the predefined location.

For example, the indication message may be a radio resource control(RRC) signaling message. This embodiment of the present disclosure isnot limited thereto.

Optionally, the first time-frequency resource includes a plurality ofresource element RE sets, each of the plurality of RE sets includes asame fixed quantity of REs, and the third time-frequency resourceincludes an RE at a preset location in each of the plurality of RE sets.

Optionally, the first time-frequency resource includes a plurality ofresource element RE sets, each of the plurality of RE sets includes asame fixed quantity of REs, and the third time-frequency resourceincludes all REs in at least one of the plurality of RE sets.

According to a second aspect, a signal transmission method is provided,and the method includes:

-   -   detecting a first time-frequency resource, where the first        time-frequency resource is a first candidate resource in a        plurality of candidate resources;    -   obtaining a second time-frequency resource and a third        time-frequency resource based on the first time-frequency        resource and a preset rule, where the third time-frequency        resource includes at least one resource element RE at a        predefined location in the first time-frequency resource, the        second time-frequency resource includes a resource other than        the third time-frequency resource in the first time-frequency        resource, the preset rule indicates the predefined location, the        second time-frequency resource is used to carry a beamformed        control channel, and the third time-frequency resource is used        to carry a reference signal of the beamformed control channel;        and    -   demodulating, based on the reference signal that is of the        beamformed control channel and that is carried in the third        time-frequency resource, the beamformed control channel carried        in the second time-frequency resource.

Therefore, in this embodiment of the present disclosure, resourcescarrying the beamformed control channel and the reference signal of thebeamformed control channel are determined, to transmit the beamformedcontrol channel and the reference signal of the beamformed controlchannel. In this way, it becomes possible to improve coverage of acontrol channel through beamforming in an existing system.

It should be understood that the second aspect corresponds to theforegoing first aspect, the first aspect is performed by a networkdevice, and the second aspect may be performed by a terminal device. Forcorresponding features of the method on a terminal side, refer to theforegoing description of the first aspect. Therefore, for brevity,detailed description is omitted.

Optionally, the first time-frequency resource includes a plurality ofresource element RE sets, each of the plurality of RE sets includes asame fixed quantity of REs, and the third time-frequency resourceincludes an RE at a preset location in each of the plurality of RE sets.

Optionally, the first time-frequency resource includes a plurality ofresource element RE sets, each of the plurality of RE sets includes asame fixed quantity of REs, and the third time-frequency resourceincludes all REs in at least one of the plurality of RE sets.

Optionally, before the detecting a first time-frequency resource, themethod further includes:

-   -   receiving an indication message, where the indication message        indicates the preset rule.

According to a third aspect, a signal transmission method is provided,including:

-   -   determining a first time-frequency resource, where the first        time-frequency resource is a first candidate resource in a        plurality of candidate resources, and the first time-frequency        resource is used to carry a beamformed control channel;    -   determining a second time-frequency resource, where the second        time-frequency resource is a second candidate resource in the        plurality of candidate resources, or the second time-frequency        resource is a resource other than the plurality of candidate        resources configured for a terminal device, and the second        time-frequency resource is used to carry a reference signal of        the beamformed control channel; and    -   respectively transmitting the beamformed control channel and the        reference signal of the beamformed control channel to the        terminal device by using the first time-frequency resource and        the second time-frequency resource.

Therefore, in this embodiment of the present disclosure, resourcescarrying the beamformed control channel and the reference signal of thebeamformed control channel are determined, to transmit the beamformedcontrol channel and the reference signal of the beamformed controlchannel. In this way, it becomes possible to improve coverage of acontrol channel through beamforming in an existing system.

In addition, a design of the beamformed control channel and thereference signal used for demodulating the beamformed control channel isused in this embodiment of the present disclosure, to improve coverageand performance of the control channel in comparison with a conventionalcontrol channel, and especially, to improve coverage of a cell using ahigh-frequency carrier. In addition, introduction of the beamformedcontrol channel has no impact on or has slight impact on compatibilityof a conventional terminal device.

It should be noted that the term “candidate resource” according to thisembodiment of the present disclosure is defined as follows:

One time-frequency resource set may be divided into a plurality oftime-frequency resource subsets, and the candidate resource is aresource that includes one or more time-frequency resource subsetsselected based on a specific rule.

For example, in an LTE system, the time-frequency resource set may betime-frequency resources corresponding to first three OFDM symbols in asubframe. The time-frequency resource subset may be a CCE or an ECCE.The candidate resource is one or more subsets selected based on thespecific rule. The candidate resource includes one CCE, two CCEs, fourCCEs, or eight CCEs, and a corresponding aggregation level isrespectively 1, 2, 4, or 8.

For example, a network device may determine the first time-frequencyresource based on an existing method for determining a PDCCH resource inLTE.

Specifically, the network device may first determine an aggregationlevel. The aggregation level is used to indicate a size of the candidateresource. For example, the network device may first determine a PDCCHformat. A PDCCH format corresponds to a specific aggregation level, theaggregation level corresponds to a quantity of CCEs carrying a PDCCH,and the quantity of CCEs corresponds to a size of a candidate resourcein the PDCCH format.

Then, the candidate resource is selected from a set of the plurality ofcandidate resources corresponding to the aggregation level, and thecandidate resource is used as the first time-frequency resource.

It should be understood that the aggregation level may include 4 and 8;1, 2, 4, and 8; or the like. For detailed description of the aggregationlevel, refer to a definition in an existing standard. Details are notdescribed herein.

It should be understood that the first time-frequency resource mayinclude a plurality of (a quantity corresponds to an aggregation level)resource element RE sets, and each of the plurality of RE sets includesa same fixed quantity of REs.

For example, in LTE, an RE set is a control channel element CCE, a PDCCHis carried by at least one CCE, and a quantity of CCEs carrying thePDCCH is determined by an aggregation level. For example, a quantity ofCCEs may be 1, 2, 4, or 8. One CCE includes nine resource element groups(REGs), and one REG includes four REs. In other words, one RE set mayinclude 36 REs. Only LTE is used as an example herein for description.In different systems, one RE set may include another quantity of REs.This embodiment of the present disclosure is not limited thereto.

In the LTE system, the first time-frequency resource may be obtainedthrough respectively aggregating one control channel element CCE, twoconsecutive CCEs, four consecutive CCEs, or eight consecutive CCEs infirst three orthogonal frequency division multiplexing OFDM symbols in asubframe for an aggregation level 1, 2, 4, or 8. For example, as shownin FIG. 5, the first time-frequency resource includes eight CCEs,respectively CCE 0 to CCE 7.

In other words, the candidate resource set herein may correspond to anexisting resource set carrying an existing PDCCH.

In this embodiment of the present disclosure, the first time-frequencyresource may be used to carry a beamformed PDCCH.

It should be understood that the plurality of candidate resources inthis embodiment of the present disclosure may include candidateresources corresponding to all aggregation levels, or may includecandidate resources corresponding to one aggregation level. This is notlimited in this embodiment of the present disclosure.

It should be understood that the foregoing describes a process ofdetermining the first time-frequency resource based on the existingmethod for determining a PDCCH resource in LTE, and describes an examplein which the first time-frequency resource may include a plurality ofCCEs. In this embodiment of the present disclosure, alternatively, thefirst time-frequency resource may be the first time-frequency resourcethat is determined by the network device based on an existing method fordetermining an EPDCCH resource in LTE. The EPDCCH is carried by at leastone ECCE. A quantity of ECCEs carrying the EPDCCH is determined based onan EPDCCH format. Each EPDCCH format corresponds to a specificaggregation level, and the aggregation level corresponds to a specificquantity of ECCEs. An EPDCCH candidate resource set may correspond to aresource set that includes a specific quantity of ECCEs corresponding toan EPDCCH format. Each ECCE may include four or eight EREGs. Theaggregation level corresponding to the EPDCCH format includes 1, 2, 4,8, 16, and 32. In other words, a corresponding first time-frequencyresource may include 1, 2, 4, 8, 16, and 32 ECCEs.

Specifically, the second time-frequency resource is a resource otherthan the first time-frequency resource, and the second time-frequencyresource is used to carry the reference signal of the beamformed controlchannel.

It should be understood that the second time-frequency resource in thisembodiment of the present disclosure has a plurality of feasiblemanners. The following separately describes in detail a case in whichthe second time-frequency resource is the second candidate resource anda case in which the second time-frequency resource is the resource otherthan the plurality of candidate resources configured for the terminaldevice.

When the second time-frequency resource is the second candidate resourcein the plurality of candidate resources,

-   -   the second time-frequency resource may be the second candidate        resource predefined in the plurality of candidate resources.

In other words, the second time-frequency resource is a predefinedresource, and the predefined resource is one of the plurality ofcandidate resources, namely, the second candidate resource.

In other words, the second resource is a predefined resource, to bespecific, a resource predefined in the system or a resource on which thenetwork device and the terminal device preagree. Both the network deviceand the terminal device learn of a location of the second resource inadvance, and the second resource carries the reference signal of thebeamformed control channel.

It should be understood that the second time-frequency resource and thefirst time-frequency resource may have a same size (for example, a sameaggregation level) or may have different sizes. This is not limited inthis embodiment of the present disclosure.

For example, the second time-frequency resource and the firsttime-frequency resource may have a same size (for example, a sameaggregation level). In other words, the second time-frequency resourceis a candidate resource other than the first time-frequency resource inthe set of the plurality of candidate resources corresponding to thefirst time-frequency resource. For example, in the LTE system, each ofaggregation levels of the first time-frequency resource and the secondtime-frequency resource is 1, 2, 4, 8, or the like.

For another example, a size of the second time-frequency resource isdifferent from a size of the second time-frequency resource. In otherwords, the second time-frequency resource is a candidate resource inanother set of candidate resources. For example, in the LTE system, anaggregation level of the first time-frequency resource is 2, and anaggregation level of the second candidate resource is 4 or the like.

In addition, when the second time-frequency resource is the secondcandidate resource in the plurality of candidate resources,

-   -   the second time-frequency resource is the second candidate        resource configured for the terminal device.

For example, the network device may send, to the terminal device, amessage that is used to configure the second resource as the secondcandidate resource. For example, the message may be an RRC signalingmessage. However, this embodiment of the present disclosure is notlimited thereto.

In addition, when the second time-frequency resource is the secondcandidate resource in the plurality of candidate resources,

-   -   the network device may determine the second candidate        time-frequency resource based on a preset mapping relationship        between the first time-frequency resource and the second        time-frequency resource.

In a case, the second candidate time-frequency resource may be one ofcandidate resources that have a same size as the first time-frequencyresource and that are in the plurality of candidate resources.

For example, the network device may determine the second time-frequencyresource based on the preset mapping relationship between the firsttime-frequency resource and the second time-frequency resource. Thesecond time-frequency resource is another candidate resource other thanthe first time-frequency resource in the candidate resources that have asame size.

For example, the mapping relationship indicates that the secondtime-frequency resource may be a candidate resource adjacent to thefirst time-frequency resource, a time-frequency resource at a fixeddistance from the first time-frequency resource, or the like.

It should be understood that the mapping relationship may be preagreedon by the network device and the terminal device, for example, may besent by the network device to the terminal device in advance. This isnot limited in this embodiment of the present disclosure.

In another case, the second candidate time-frequency resource is acandidate resource that is in candidate resources of a specified size inthe plurality of candidate resources and that does not overlap with thefirst time-frequency resource.

For example, the specified size may be an aggregation level 1, 2, 4, 8,or the like. The specified size may be the same as or different from thesize of the first time-frequency resource. This is not limited in thisembodiment of the present disclosure.

For example, the specified size may be an aggregation level 4, and thesecond time-frequency resource may be a candidate resource that is in aplurality of candidate resources whose aggregation levels are 4 and thathas a smallest or a largest number in candidate resources that do notoverlap with the first time-frequency resource. This embodiment of thepresent disclosure is not limited thereto. However, it should beunderstood that the network device and the terminal device need to havea consistent rule for determining the second time-frequency resource.For example, both the network device and the terminal device agree thatthe second time-frequency resource is a candidate resource that has asmallest number in a set of a plurality of candidate resources of aspecified size and that does not overlap with the first time-frequencyresource.

When the second time-frequency resource is the resource other than theplurality of candidate resources configured for the terminal device,

-   -   the second time-frequency resource includes a resource other        than the first time-frequency resource configured by the network        device for the terminal device.

For example, the second time-frequency resource includes atime-frequency resource corresponding to another reference signal otherthan a common reference signal (CRS), or the second time-frequencyresource includes a time-frequency resource corresponding to a datachannel.

Specifically, the network device may send an indication message forconfiguration to the terminal device. The indication message indicates alocation of the second time-frequency resource. For example, theindication message may be an RRC signaling message. However, thisembodiment of the present disclosure is not limited thereto.

For example, in LTE, the second time-frequency resource may be atime-frequency resource in a fourth to a 14^(th) OFDM symbols in asubframe.

For example, the second time-frequency resource may include a resourcethat corresponds to a PDSCH and that is in the fourth to the 14^(th)OFDM symbols in the subframe.

Specifically, the second time-frequency resource may include at leastone RE in a zero-power user status information-reference signalzero-power CSI-RS resource configured for the user equipment.

Alternatively, the third time-frequency resource may include at leastone RE that is in the fourth to the 14^(th) OFDM symbols in the subframeand that is in a non-zero power user status information-reference signalnon-zero power CSI-RS resource configured for the user equipment.

Therefore, in this embodiment of the present disclosure, the existingfirst time-frequency resource carrying a control channel carries thebeamformed control channel, and another resource (the secondtime-frequency resource) carries the reference signal of the beamformedcontrol channel, to send the beamformed control channel and thereference signal of the beamformed control channel. In this way, itbecomes possible to improve coverage of a control channel throughbeamforming in the existing system.

In addition, a design of the beamformed control channel and thereference signal used for demodulating the beamformed control channel isused in this embodiment of the present disclosure, to improve coverageand performance of the control channel in comparison with a conventionalcontrol channel, and especially, to improve coverage of a cell using ahigh-frequency carrier. In addition, introduction of the beamformedcontrol channel has no impact on or has slight impact on compatibilityof a conventional terminal device.

According to a fourth aspect, a signal transmission method is provided,including:

-   -   detecting a first time-frequency resource, where the first        time-frequency resource is a first candidate resource in a        plurality of candidate resources, and the first time-frequency        resource is used to carry a beamformed control channel;    -   detecting a second time-frequency resource, where the second        time-frequency resource is a second candidate resource in the        plurality of candidate resources, or the second time-frequency        resource is a resource other than the plurality of candidate        resources configured for a terminal device, and the second        time-frequency resource is used to carry a reference signal of        the beamformed control channel; and    -   demodulating, based on the reference signal that is of the        beamformed control channel and that is carried in the second        time-frequency resource, the beamformed control channel carried        in the first time-frequency resource.

Therefore, in this embodiment of the present disclosure, resourcescarrying the beamformed control channel and the reference signal of thebeamformed control channel are determined, to transmit the beamformedcontrol channel and the reference signal of the beamformed controlchannel. In this way, it becomes possible to improve coverage of acontrol channel through beamforming in an existing system.

In addition, a design of the beamformed control channel and thereference signal used for demodulating the beamformed control channel isused in this embodiment of the present disclosure, to improve coverageand performance of the control channel in comparison with a conventionalcontrol channel, and especially, to improve coverage of a cell using ahigh-frequency carrier. In addition, introduction of the beamformedcontrol channel has no impact on or has slight impact on compatibilityof a conventional terminal device.

It should be understood that the fourth aspect corresponds to theforegoing third aspect, the third aspect is performed by a networkdevice, and the fourth aspect may be performed by the terminal device.For corresponding features of the method on a terminal side, refer tothe foregoing description of the third aspect. Therefore, for brevity,detailed description is omitted.

Optionally, when the second time-frequency resource is the secondcandidate resource in the plurality of candidate resources,

-   -   the second time-frequency resource is the second candidate        resource predefined in the plurality of candidate resources.

Optionally, when the second time-frequency resource is the secondcandidate resource in the plurality of candidate resources,

-   -   the second time-frequency resource is the second candidate        resource configured for the terminal device.

Optionally, when the second time-frequency resource is the resourceother than the plurality of candidate resources configured for theterminal device,

-   -   the second time-frequency resource includes a time-frequency        resource corresponding to another reference signal other than a        common reference signal (CRS), or the second time-frequency        resource includes a time-frequency resource corresponding to a        data channel.

Optionally, before the detecting a second time-frequency resource, themethod further includes:

-   -   receiving an indication message sent by the network device,        where the indication message indicates a location of the second        time-frequency resource.

Optionally, when the second time-frequency resource is the secondcandidate resource in the plurality of candidate resources,

-   -   the second time-frequency resource is the second candidate        resource determined based on a preset mapping relationship        between the first time-frequency resource and the second        time-frequency resource.

Optionally, the second candidate time-frequency resource is one ofcandidate resources that have a same size as the first time-frequencyresource and that are in the plurality of candidate resources.

Optionally, the second candidate time-frequency resource is a candidateresource that is in candidate resources of a specified size in theplurality of candidate resources and that does not overlap with thefirst time-frequency resource.

According to a fifth aspect, a network device is provided and isconfigured to perform the method in the first aspect, any possibleimplementation of the first aspect, the third aspect, or any possibleimplementation of the third aspect. Specifically, the network deviceincludes a unit configured to perform the foregoing method.

According to a sixth aspect, a terminal device is provided and isconfigured to perform the method in the second aspect, any possibleimplementation of the second aspect, the fourth aspect, or any possibleimplementation of the fourth aspect. Specifically, the terminal deviceincludes a unit configured to perform the foregoing method.

According to a seventh aspect, a computer-readable medium is providedand is configured to store a computer program. The computer programincludes an instruction used to perform the method in the first aspect,any possible implementation of the first aspect, the third aspect, orany possible implementation of the third aspect.

According to an eighth aspect, a computer-readable medium is providedand is configured to store a computer program. The computer programincludes an instruction used to perform the method in the second aspect,any possible implementation of the second aspect, the fourth aspect, orany possible implementation of the fourth aspect.

BRIEF DESCRIPTION OF DRAWINGS

To describe the technical solutions in the embodiments of the presentdisclosure more clearly, the following briefly describes theaccompanying drawings required for describing the embodiments of thepresent disclosure. Apparently, the accompanying drawings in thefollowing description show merely some embodiments of the presentdisclosure, and a person of ordinary skill in the art may still deriveother drawings from these accompanying drawings without creativeefforts.

FIG. 1 is a schematic diagram of beam coverage;

FIG. 2 is another schematic diagram of beam coverage;

FIG. 3 is another schematic diagram of beam coverage;

FIG. 4 is a schematic flowchart of a signal transmission methodaccording to an embodiment of the present disclosure;

FIG. 5 is a schematic diagram of resource distribution according to anembodiment of the present disclosure;

FIG. 6 is a schematic diagram of resource distribution according toanother embodiment of the present disclosure;

FIG. 7 is a schematic diagram of resource distribution according toanother embodiment of the present disclosure;

FIG. 8 is a schematic flowchart of a signal transmission methodaccording to another embodiment of the present disclosure;

FIG. 9 is a schematic diagram of resource distribution according toanother embodiment of the present disclosure;

FIG. 10 is a schematic block diagram of a network device according to anembodiment of the present disclosure;

FIG. 11 is a schematic block diagram of a terminal device according toan embodiment of the present disclosure;

FIG. 12 is a schematic block diagram of a network device according toanother embodiment of the present disclosure;

FIG. 13 is a schematic block diagram of a terminal device according toanother embodiment of the present disclosure;

FIG. 14 is a schematic block diagram of a network device according toanother embodiment of the present disclosure;

FIG. 15 is a schematic block diagram of a terminal device according toanother embodiment of the present disclosure;

FIG. 16 is a schematic block diagram of a network device according toanother embodiment of the present disclosure; and

FIG. 17 is a schematic block diagram of a terminal device according toanother embodiment of the present disclosure.

DESCRIPTION OF EMBODIMENTS

The following clearly describes the technical solutions in theembodiments of the present disclosure with reference to the accompanyingdrawings in the embodiments of the present disclosure. Apparently, thedescribed embodiments are some but not all of the embodiments of thepresent disclosure. All other embodiments obtained by a person ofordinary skill in the art based on the embodiments of the presentdisclosure without creative efforts shall fall within the protectionscope of the present disclosure.

It should be understood that the technical solutions of the embodimentsof the present disclosure can be applied to various communicationssystems such as a Global System for Mobile Communications (GSM) system,a Code Division Multiple Access (CDMA) system, a Wideband Code DivisionMultiple Access (WCDMA) system, a general packet radio service (GPRS), aLong Term Evolution (LTE) system, an LTE frequency division duplex (FDD)system, LTE time division duplex (TDD), a Universal MobileTelecommunications System (UMTS), and a Worldwide Interoperability forMicrowave Access (WiMAX) communications system. In the embodiments ofthe present disclosure, only LTE is used as an example for description.The present disclosure is not limited thereto.

It should also be understood that, in the embodiments of the presentdisclosure, a network device may be a base transceiver station (BTS) ina GSM system or a Code Division Multiple Access (CDMA) system, a NodeB(NB) in a WCDMA system, an evolved NodeB (Evolved NodeB, eNB, or eNodeB)in an LTE system, or a radio controller in a cloud radio access network(CRAN). Alternatively, a network device may be a relay station, anaccess point, an in-vehicle device, a wearable device, a network-sidedevice in a future 5G network, a network device in a future evolvedpublic land mobile network (PLMN), or the like.

A terminal device may be referred to as an access terminal, a userequipment (UE), a subscriber unit, a subscriber station, a mobilestation, a mobile console, a remote station, a remote terminal, a mobiledevice, a user terminal, a terminal, a wireless communications device, auser agent, a user apparatus, or the like. The access terminal may be acellular phone, a cordless phone, a Session Initiation Protocol (SIP)phone, a wireless local loop (WLL) station, a personal digital assistant(PDA), a handheld device having a wireless communications function, acomputing device, another processing device connected to a wirelessmodem, an in-vehicle device, a wearable device, a terminal device in afuture 5G network, a terminal device in a future evolved public landmobile network (PLMN), or the like.

It should be noted that the term “candidate resource” according to theembodiments of the present disclosure is defined as follows:

One time-frequency resource set may be divided into a plurality oftime-frequency resource subsets, and the candidate resource is aresource that includes one or more time-frequency resource subsetsselected based on a specific rule.

For example, in an LTE system, the time-frequency resource set may betime-frequency resources corresponding to first three OFDM symbols in asubframe. The time-frequency resource subset may be a CCE or an ECCE.The candidate resource is one or more subsets selected based on thespecific rule. The candidate resource includes one CCE, two CCEs, fourCCEs, or eight CCEs, and a corresponding aggregation level isrespectively 1, 2, 4, or 8.

FIG. 4 is a schematic flowchart of a signal sending method according toan embodiment of the present disclosure. The method shown in FIG. 4 maybe applied to the foregoing various communications systems. In FIG. 4, adetailed description is provided by using only an example in which acontrol channel is a PDCCH in an LTE system. However, this embodiment ofthe present disclosure is not limited thereto. In other words, variousterms in this embodiment of the present disclosure may have differentnames in different systems. This is not limited in this embodiment ofthe present disclosure. A communications system in this embodiment ofthe present disclosure includes a network device and a terminal device.A method 400 shown in FIG. 4 includes the following steps.

410. The network device determines a first time-frequency resource.

Specifically, the network device determines the first time-frequencyresource. The first time-frequency resource is a first candidateresource in a plurality of candidate resources.

In other words, the first time-frequency resource is a candidateresource in a set of the plurality of candidate resources.

For example, the network device may determine the first time-frequencyresource based on an existing method for determining a PDCCH resource inLTE.

Specifically, the network device may first determine an aggregationlevel. The aggregation level is used to indicate a size of the candidateresource. For example, the network device may first determine a PDCCHformat. A PDCCH format corresponds to a specific aggregation level, theaggregation level corresponds to a quantity of CCEs carrying a PDCCH,and the quantity of CCEs corresponds to a size of a candidate resourcein the PDCCH format.

Then, the candidate resource is selected from a set of a plurality ofcandidate resources corresponding to the aggregation level, and thecandidate resource is used as the first time-frequency resource.

It should be understood that the aggregation level may include 4 and 8;1, 2, 4, and 8; or the like. For detailed description of the aggregationlevel, refer to a definition in an existing standard. Details are notdescribed herein.

It should be understood that the first time-frequency resource mayinclude a plurality of (a quantity corresponds to an aggregation level)resource element RE sets, and each of the plurality of RE sets includesa same fixed quantity of REs.

For example, in LTE, an RE set is a control channel element CCE, a PDCCHis carried by at least one CCE, and a quantity of CCEs carrying thePDCCH is determined by an aggregation level. For example, a quantity ofCCEs may be 1, 2, 4, or 8. One CCE includes nine resource element groups(REGs), and one REG includes four REs. In other words, one RE set mayinclude 36 REs. Only LTE is used as an example herein for description.In different systems, one RE set may include another quantity of REs.This embodiment of the present disclosure is not limited thereto.

In the LTE system, the first time-frequency resource may be obtainedthrough respectively aggregating one control channel element CCE, twoconsecutive CCEs, four consecutive CCEs, or eight consecutive CCEs infirst three orthogonal frequency division multiplexing OFDM symbols in asubframe for an aggregation level 1, 2, 4, or 8. For example, as shownin FIG. 5, the first time-frequency resource includes eight CCEs,respectively CCE 0 to CCE 7.

In other words, the candidate resource set herein may correspond to anexisting resource set carrying an existing PDCCH.

In this embodiment of the present disclosure, the first time-frequencyresource may be used to carry a beamformed PDCCH, and may be used tocarry a reference signal of the beamformed PDCCH.

It should be understood that the plurality of candidate resources inthis embodiment of the present disclosure may include candidateresources corresponding to all aggregation levels, or may includecandidate resources corresponding to one aggregation level. This is notlimited in this embodiment of the present disclosure.

It should be understood that the foregoing describes a process ofdetermining the first time-frequency resource based on the existingmethod for determining a PDCCH resource in LTE, and describes an examplein which the first time-frequency resource may include a plurality ofCCEs. In this embodiment of the present disclosure, alternatively, thefirst time-frequency resource may be the first time-frequency resourcethat is determined by the network device based on an existing method fordetermining an EPDCCH resource in LTE. The EPDCCH is carried by at leastone ECCE. A quantity of ECCEs carrying the EPDCCH is determined based onan EPDCCH format. Each EPDCCH format corresponds to a specificaggregation level, and the aggregation level corresponds to a specificquantity of ECCEs. An EPDCCH candidate resource set may correspond to aresource set that includes a specific quantity of ECCEs corresponding toan EPDCCH format. Each ECCE may include four or eight EREGs. Theaggregation level corresponding to the EPDCCH format includes 1, 2, 4,8, 16, and 32. In other words, a corresponding first time-frequencyresource may include 1, 2, 4, 8, 16, and 32 ECCEs.

Therefore, in this embodiment of the present disclosure, based on theexisting method, the first resource is determined for carrying abeamformed control channel and a reference signal subsequently. Becausethis is the same as an existing manner, sending a beamformed controlchannel and a reference signal of the beamformed control channel in thisembodiment of the present disclosure has no impact on or has slightimpact on compatibility of a conventional terminal device.

420. The network device obtains a second time-frequency resource and athird time-frequency resource.

Specifically, the network device obtains the second time-frequencyresource and the third time-frequency resource based on the firsttime-frequency resource and a preset rule. The third time-frequencyresource includes at least one resource element RE at a predefinedlocation in the first time-frequency resource, and the secondtime-frequency resource includes a resource other than the thirdtime-frequency resource in the first time-frequency resource. The presetrule indicates the predefined location. The second time-frequencyresource is used to carry a beamformed control channel, and the thirdtime-frequency resource is used to carry a reference signal of thebeamformed control channel.

In other words, in this embodiment of the present disclosure, theexisting first time-frequency resource carrying a control channelcarries both the beamformed control channel and the reference signal ofthe beamformed control channel, to send the beamformed control channeland the reference signal of the beamformed control channel. In this way,it becomes possible to improve coverage of a control channel throughbeamforming in the existing system.

In addition, a design of the beamformed control channel and thereference signal used for demodulating the beamformed control channel isused in this embodiment of the present disclosure, to improve coverageand performance of the control channel in comparison with a conventionalcontrol channel, and especially, to improve coverage of a cell using ahigh-frequency carrier. In addition, introduction of the beamformedcontrol channel has no impact on or has slight impact on compatibilityof a conventional terminal device.

It should be understood that the preset rule in this embodiment of thepresent disclosure may be a rule preset in the system. In other words,the preset rule may be a rule on which the network device and theterminal device preagree. After the first resource is determined, thenetwork device and the terminal device may obtain the second resourceand the third resource based on the preset rule.

Specifically, the third time-frequency resource may include the at leastone resource element RE in the first time-frequency resource, and thesecond time-frequency resource includes the resource other than thethird time-frequency resource in the first time-frequency resource.

Specifically, the third time-frequency resource may include an RE in atleast one of the foregoing plurality of RE sets.

For example, the third time-frequency resource may include only one REin one RE set; or may include REs in a plurality of RE sets, where oneRE set has only one RE that belongs to the third time-frequencyresource; or may include an RE in each RE set.

For another example, the third time-frequency resource may include an REat a preset location in each of the foregoing plurality of RE sets.

For example, in the LTE system, the preset location may be an n^(th) REin each REG in each CCE. Herein, n may be 1, 2, 3, or 4. For example, asshown in FIG. 6, the first time-frequency resource includes eight CCEs,and the third time-frequency resource may include a second RE (forexample, an RE 1 in a REG 0) in each REG in each CCE. In FIG. 3, forease of description, a CCE 3 is used as an example to show REs includedin the first time-frequency resource. REs at corresponding locations inother CCEs all belong to the third time-frequency resource. This is notshown in FIG. 6.

It should be understood that in FIG. 6, for ease of description, adescription is provided in a case in which preset locations in RE setsare the same, to be specific, the preset locations are a second RE ineach REG. However, in this embodiment of the present disclosure, presetlocations in different RE sets may be the same or may be different. Thisis not limited in this embodiment of the present disclosure.

Alternatively, the third time-frequency resource may include all REs inat least one of the foregoing plurality of RE sets.

For example, the third time-frequency resource may include only all REsin one RE set, or may include all REs in the plurality of RE sets.

For example, when the first time-frequency resource includes a pluralityof CCEs, the third time-frequency resource may include all REs in atleast one of the plurality of CCEs.

It should be understood that the third time-frequency resource mayinclude all the REs in the at least one of the plurality of CCEsprovided that the third time-frequency resource is less than the firsttime-frequency resource; and the resource other than the thirdtime-frequency resource in the first time-frequency resource is thesecond time-frequency resource. Similarly, in this embodiment of thepresent disclosure, the second resource also needs to be less than thefirst time-frequency resource, and a resource other than the secondtime-frequency resource in the first time-frequency resource is thethird time-frequency resource.

For example, as shown in FIG. 7, the first time-frequency resourceincludes eight CCEs, and the third time-frequency resource may includeone CCE, for example, all REs in the CCE 3.

It should be understood that the preset rule may be a rule on which thenetwork device and the terminal device preagree. After the firstresource is determined, the network device and the terminal device mayobtain the second resource and the third resource based on the presetrule. Alternatively, the preset rule may be notified by the networkdevice to the terminal device by using signaling. To be specific, thenetwork device sends a message in advance to agree on the preset rulewith the terminal device.

Correspondingly, in another embodiment, before 410, the method mayfurther include: sending an indication message to the terminal device,where the indication message indicates the predefined location.

For example, the indication message may be an RRC signaling message.This embodiment of the present disclosure is not limited thereto.

430. Send a beamformed control channel and a reference signal of thebeamformed control channel.

Specifically, the network device respectively transmits, to the terminaldevice by using the second time-frequency resource and the thirdtime-frequency resource, the beamformed control channel and thereference signal RS corresponding to the beamformed control channel.

Therefore, the terminal device may demodulate the beamformed controlchannel based on the received reference signal of the beamformed controlchannel. For example, the terminal device receives a signal on acandidate resource in the candidate resource set in searching space.When blind detection is performed on a candidate resource, for example,the candidate resource may be the first time-frequency resource. Theterminal device demodulates, based on the reference signal on the thirdtime-frequency resource at the predefined location, the control channelcarried in the second time-frequency resource; decodes information bitsof the received control channel; performs CRC check based on an ID ofthe terminal device; and if the check succeeds, it indicates that thecontrol channel that is sent to the terminal device is successivelyreceived, in other words, the blindly detected candidate resource is thefirst time-frequency resource. If the check fails, it indicates that abase station does not send the control channel on the candidate resourceto the terminal device, in other words, the blindly detected candidateresource is not the first time-frequency resource.

Therefore, in this embodiment of the present disclosure, resourcescarrying the beamformed control channel and the reference signal of thebeamformed control channel are determined, to transmit the beamformedcontrol channel and the reference signal of the beamformed controlchannel. In this way, it becomes possible to improve coverage of acontrol channel through beamforming in an existing system.

In addition, a design of the beamformed control channel and thereference signal used for demodulating the beamformed control channel isused in this embodiment of the present disclosure, to improve coverageand performance of the control channel in comparison with a conventionalcontrol channel, and especially, to improve coverage of a cell using ahigh-frequency carrier. In addition, introduction of the beamformedcontrol channel has no impact on or has slight impact on compatibilityof a conventional terminal device.

The foregoing describes in detail the signal sending method according tothe embodiments of the present disclosure with reference to FIG. 4 toFIG. 7. The following describes in detail a signal sending methodaccording to another embodiment of the present disclosure with referenceto FIG. 8.

It should be understood that a difference between FIG. 7 and FIG. 8 isthat a first time-frequency resource in FIG. 7 is used to transmit botha beamformed control channel and a reference signal of the beamformedcontrol channel, but a first time-frequency resource in FIG. 8 is usedto carry only a beamformed control channel, and the beamformed controlchannel may be carried in another resource, for example, a candidateresource in a candidate resource set or a resource used to carry anotherchannel or a reference signal. Specifically, the following describes thesignal sending method in detail with reference to FIG. 8.

FIG. 8 is a schematic flowchart of a signal sending method according toan embodiment of the present disclosure. The method shown in FIG. 8 maybe applied to the foregoing various communications systems. In FIG. 8, adetailed description is provided by using only an example in which acontrol channel is a PDCCH in an LTE system. However, this embodiment ofthe present disclosure is not limited thereto. In other words, variousterms in this embodiment of the present disclosure may have differentnames in different systems. This is not limited in this embodiment ofthe present disclosure. A communications system in this embodiment ofthe present disclosure includes a network device and a terminal device.A method 800 shown in FIG. 8 includes the following steps.

810. The network device determines a first time-frequency resource.

Specifically, the network device determines the first time-frequencyresource. The first time-frequency resource is a first candidateresource in a plurality of candidate resources, and the firsttime-frequency resource is used to carry a beamformed control channel.

In other words, the first time-frequency resource is a candidateresource in a set of the plurality of candidate resources.

For example, the network device may determine the first time-frequencyresource based on an existing method for determining a PDCCH resource inLTE.

Specifically, the network device may first determine an aggregationlevel. The aggregation level is used to indicate a size of the candidateresource. For example, the network device may first determine a PDCCHformat. A PDCCH format corresponds to a specific aggregation level, theaggregation level corresponds to a quantity of CCEs carrying a PDCCH,and the quantity of CCEs corresponds to a size of a candidate resourcein the PDCCH format.

Then, the candidate resource is selected from a set of a plurality ofcandidate resources corresponding to the aggregation level, and thecandidate resource is used as the first time-frequency resource.

It should be understood that the aggregation level may include 4 and 8;1, 2, 4, and 8; or the like. For detailed description of the aggregationlevel, refer to a definition in an existing standard. Details are notdescribed herein.

It should be understood that the first time-frequency resource mayinclude a plurality of (a quantity corresponds to an aggregation level)resource element RE sets, and each of the plurality of RE sets includesa same fixed quantity of REs.

For example, in LTE, an RE set is a control channel element CCE, a PDCCHis carried by at least one CCE, and a quantity of CCEs carrying thePDCCH is determined by an aggregation level. For example, a quantity ofCCEs may be 1, 2, 4, or 8. One CCE includes nine resource element groups(REGs), and one REG includes four REs. In other words, one RE set mayinclude 36 REs. Only LTE is used as an example herein for description.In different systems, one RE set may include another quantity of REs.This embodiment of the present disclosure is not limited thereto.

In the LTE system, the first time-frequency resource may be obtainedthrough respectively aggregating one control channel element CCE, twoconsecutive CCEs, four consecutive CCEs, or eight consecutive CCEs infirst three orthogonal frequency division multiplexing OFDM symbols in asubframe for an aggregation level 1, 2, 4, or 8. For example, as shownin FIG. 5, the first time-frequency resource includes eight CCEs,respectively CCE 0 to CCE 7.

In other words, the candidate resource set herein may correspond to anexisting resource set carrying an existing PDCCH.

In this embodiment of the present disclosure, the first time-frequencyresource may be used to carry a beamformed PDCCH.

It should be understood that the plurality of candidate resources inthis embodiment of the present disclosure may include candidateresources corresponding to all aggregation levels, or may includecandidate resources corresponding to one aggregation level. This is notlimited in this embodiment of the present disclosure.

It should be understood that the foregoing describes a process ofdetermining the first time-frequency resource based on the existingmethod for determining a PDCCH resource in LTE, and describes an examplein which the first time-frequency resource may include a plurality ofCCEs. In this embodiment of the present disclosure, alternatively, thefirst time-frequency resource may be the first time-frequency resourcethat is determined by the network device based on an existing method fordetermining an EPDCCH resource in LTE. The EPDCCH is carried by at leastone ECCE. A quantity of ECCEs carrying the EPDCCH is determined based onan EPDCCH format. Each EPDCCH format corresponds to a specificaggregation level, and the aggregation level corresponds to a specificquantity of ECCEs. An EPDCCH candidate resource set may correspond to aresource set that includes a specific quantity of ECCEs corresponding toan EPDCCH format. Each ECCE may include four or eight EREGs. Theaggregation level corresponding to the EPDCCH format includes 1, 2, 4,8, 16, and 32. In other words, a corresponding first time-frequencyresource may include 1, 2, 4, 8, 16, and 32 ECCEs.

Therefore, in this embodiment of the present disclosure, based on theexisting method, the first resource is determined for carrying abeamformed control channel subsequently. Because this is the same as anexisting manner, sending a beamformed control channel in this embodimentof the present disclosure has no impact on or has slight impact oncompatibility of a conventional terminal device.

820. The network device determines a second time-frequency resource.

Specifically, the second time-frequency resource is a second candidateresource in the plurality of candidate resources, or the secondtime-frequency resource is a resource other than the plurality ofcandidate resources configured for the terminal device, and the secondtime-frequency resource is used to carry a reference signal of thebeamformed control channel.

In other words, the second time-frequency resource may be a resourceother than the first time-frequency resource and a third time-frequencyresource, and the third time-frequency resource includes atime-frequency resource corresponding to a reference signal of anothercontrol channel other than the beamformed control channel. A beam of theanother control channel is different from a beam of the beamformedcontrol channel.

The following separately describes in detail a case in which the secondtime-frequency resource is the second candidate resource and a case inwhich the second time-frequency resource is the resource other than theplurality of candidate resources configured for the terminal device.

When the second time-frequency resource is the second candidate resourcein the plurality of candidate resources,

-   -   the second time-frequency resource may be the second candidate        resource predefined in the plurality of candidate resources.

In other words, the second time-frequency resource is a predefinedresource, and the predefined resource is one of the plurality ofcandidate resources, namely, the second candidate resource.

In other words, the second resource is a predefined resource, to bespecific, a resource predefined in the system or a resource on which thenetwork device and the terminal device preagree. Both the network deviceand the terminal device learn of a location of the second resource inadvance, and the second resource carries the reference signal of thebeamformed control channel.

It should be understood that the second time-frequency resource and thefirst time-frequency resource may have a same size (for example, a sameaggregation level) or may have different sizes. This is not limited inthis embodiment of the present disclosure.

For example, the second time-frequency resource and the firsttime-frequency resource may have a same size (for example, a sameaggregation level). In other words, the second time-frequency resourceis a candidate resource other than the first time-frequency resource inthe set of the plurality of candidate resources corresponding to thefirst time-frequency resource. For example, in the LTE system, each ofaggregation levels of the first time-frequency resource and the secondtime-frequency resource is 1, 2, 4, 8, or the like.

For another example, a size of the second time-frequency resource isdifferent from a size of the second time-frequency resource. In otherwords, the second time-frequency resource is a candidate resource inanother set of candidate resources. For example, in the LTE system, anaggregation level of the first time-frequency resource is 2, and anaggregation level of the second candidate resource is 4 or the like.

In addition, when the second time-frequency resource is the secondcandidate resource in the plurality of candidate resources,

-   -   the second time-frequency resource is the second candidate        resource configured for the terminal device.

For example, the network device may send, to the terminal device, amessage that is used to configure the second resource as the secondcandidate resource. For example, the message may be an RRC signalingmessage. However, this embodiment of the present disclosure is notlimited thereto.

In addition, when the second time-frequency resource is the secondcandidate resource in the plurality of candidate resources,

-   -   the network device may determine the second candidate        time-frequency resource based on a preset mapping relationship        between the first time-frequency resource and the second        time-frequency resource.

In a case, the second candidate time-frequency resource may be one ofcandidate resources that have a same size as the first time-frequencyresource and that are in the plurality of candidate resources.

For example, the network device may determine the second time-frequencyresource based on the preset mapping relationship between the firsttime-frequency resource and the second time-frequency resource. Thesecond time-frequency resource is another candidate resource other thanthe first time-frequency resource in the candidate resources that have asame size.

For example, the mapping relationship indicates that the secondtime-frequency resource may be a candidate resource adjacent to thefirst time-frequency resource, a time-frequency resource at a fixeddistance from the first time-frequency resource, or the like.

For example, as shown in FIG. 9, the candidate resource set includes 10candidate resources, respectively a candidate resource 1 to a candidateresource 10. If the mapping relationship indicates that the secondtime-frequency resource may be a first right-adjacent candidate resourceof the first time-frequency resource, the second time-frequency resourceis a candidate resource 6 when the first time-frequency resource is acandidate resource 5.

For another example, if the mapping relationship indicates that thesecond time-frequency resource may be a candidate resource at a distanceof 2 to the first time-frequency resource on the right, the secondtime-frequency resource is a candidate resource 8 at a distance of 2 toa candidate resource 5 on the right when the first time-frequencyresource is the candidate resource 5.

It should be noted that different candidate resources may overlap inactual application, there may be a distance between adjacent candidateresources, and FIG. 9 describes only an example of candidate resourcesfor ease of description. However, this is not limited in this embodimentof the present disclosure.

It should be understood that the mapping relationship may be preagreedon by the network device and the terminal device, for example, may besent by the network device to the terminal device in advance. This isnot limited in this embodiment of the present disclosure.

In another case, the second candidate time-frequency resource is acandidate resource that is in candidate resources of a specified size inthe plurality of candidate resources and that does not overlap with thefirst time-frequency resource.

For example, the specified size may be an aggregation level 1, 2, 4, 8,or the like. The specified size may be the same as or different from thesize of the first time-frequency resource. This is not limited in thisembodiment of the present disclosure.

For example, the specified size may be an aggregation level 4, and thesecond time-frequency resource may be a candidate resource that is in aplurality of candidate resources whose aggregation levels are 4 and thathas a smallest or a largest number in candidate resources that do notoverlap with the first time-frequency resource. This embodiment of thepresent disclosure is not limited thereto. However, it should beunderstood that the network device and the terminal device need to havea consistent rule for determining the second time-frequency resource.For example, both the network device and the terminal device agree thatthe second time-frequency resource is a candidate resource that has asmallest number in a set of a plurality of candidate resources of aspecified size and that does not overlap with the first time-frequencyresource.

When the second time-frequency resource is the resource other than theplurality of candidate resources configured for the terminal device,

-   -   the second time-frequency resource includes a resource other        than the first time-frequency resource configured by the network        device for the terminal device.

For example, the second time-frequency resource includes atime-frequency resource corresponding to another reference signal otherthan a common reference signal (CRS), or the second time-frequencyresource includes a time-frequency resource corresponding to a datachannel.

Specifically, the network device may send an indication message forconfiguration to the terminal device. The indication message indicates alocation of the second time-frequency resource. For example, theindication message may be an RRC signaling message. However, thisembodiment of the present disclosure is not limited thereto.

For example, in LTE, the second time-frequency resource may be atime-frequency resource in a fourth to a 14^(th) OFDM symbols in asubframe.

For example, the second time-frequency resource may include a resourcethat corresponds to a PDSCH and that is in the fourth to the 14^(th)OFDM symbols in the subframe.

Specifically, the second time-frequency resource may include at leastone RE in a zero-power user status information-reference signalzero-power CSI-RS resource configured for the user equipment.

Alternatively, the third time-frequency resource may include at leastone RE that is in the fourth to the 14^(th) OFDM symbols in the subframeand that is in a non-zero power user status information-reference signalnon-zero power CSI-RS resource configured for the user equipment.

Therefore, in this embodiment of the present disclosure, the existingfirst time-frequency resource carrying a control channel carries thebeamformed control channel, and another resource (the secondtime-frequency resource) carries the reference signal of the beamformedcontrol channel, to send the beamformed control channel and thereference signal of the beamformed control channel. In this way, itbecomes possible to improve coverage of a control channel throughbeamforming in the existing system.

In addition, a design of the beamformed control channel and thereference signal used for demodulating the beamformed control channel isused in this embodiment of the present disclosure, to improve coverageand performance of the control channel in comparison with a conventionalcontrol channel, and especially, to improve coverage of a cell using ahigh-frequency carrier. In addition, introduction of the beamformedcontrol channel has no impact on or has slight impact on compatibilityof a conventional terminal device.

830. Send a beamformed control channel and a reference signal of thebeamformed control channel.

Specifically, the network device respectively transmits, to the terminaldevice by using the first time-frequency resource and the secondtime-frequency resource, the beamformed control channel and thereference signal RS corresponding to the beamformed control channel.

Therefore, the terminal device may demodulate the beamformed controlchannel based on the received reference signal of the beamformed controlchannel. For example, the terminal device receives a signal on acandidate resource in the candidate resource set in searching space.When blind detection is performed on a candidate resource, for example,the candidate resource may be the first time-frequency resource.

The terminal device detects the second time-frequency resource. Theterminal device may determine the reference signal on the secondtime-frequency resource in one of the foregoing four manners. Theterminal device demodulates, based on the reference signal on the secondtime-frequency resource, the control channel carried in the firsttime-frequency resource; decodes information bits of the receivedcontrol channel; performs CRC check based on an ID of the terminaldevice; and if the check succeeds, it indicates that the control channelthat is sent to the terminal device is successively received, in otherwords, the blindly detected candidate resource is the firsttime-frequency resource. If the check fails, it indicates that a basestation does not send the control channel on the candidate resource tothe terminal device, in other words, the blindly detected candidateresource is not the first time-frequency resource.

Therefore, in this embodiment of the present disclosure, resourcescarrying the beamformed control channel and the reference signal of thebeamformed control channel are determined, to transmit the beamformedcontrol channel and the reference signal of the beamformed controlchannel. In this way, it becomes possible to improve coverage of acontrol channel through beamforming in an existing system.

In addition, a design of the beamformed control channel and thereference signal used for demodulating the beamformed control channel isused in this embodiment of the present disclosure, to improve coverageand performance of the control channel in comparison with a conventionalcontrol channel, and especially, to improve coverage of a cell using ahigh-frequency carrier. In addition, introduction of the beamformedcontrol channel has no impact on or has slight impact on compatibilityof a conventional terminal device.

The foregoing describes in detail the signal sending method according tothe embodiments of the present disclosure with reference to FIG. 4 toFIG. 9. The following describes a device configured for signal phasesynchronization in a communications system according to embodiments ofthe present disclosure with reference to FIG. 10 to FIG. 17.

FIG. 10 is a schematic block diagram of a network device 1000 fortransmitting a signal according to an embodiment of the presentdisclosure. As shown in FIG. 10, the network device 1000 includes:

-   -   a determining unit 1010, configured to determine a first        time-frequency resource, where the first time-frequency resource        is a first candidate resource in a plurality of candidate        resources;    -   an obtaining unit 1020, configured to obtain a second        time-frequency resource and a third time-frequency resource        based on the first time-frequency resource and a preset rule,        where the third time-frequency resource includes at least one        resource element RE at a predefined location in the first        time-frequency resource, the second time-frequency resource        includes a resource other than the third time-frequency resource        in the first time-frequency resource, the preset rule indicates        the predefined location, the second time-frequency resource is        used to carry a beamformed control channel, and the third        time-frequency resource is used to carry a reference signal of        the beamformed control channel; and    -   a sending unit 1030, configured to respectively transmit the        beamformed control channel and the reference signal of the        beamformed control channel to a terminal device by using the        second time-frequency resource and the third time-frequency        resource.

Therefore, in this embodiment of the present disclosure, resourcescarrying the beamformed control channel and the reference signal of thebeamformed control channel are determined, to transmit the beamformedcontrol channel and the reference signal of the beamformed controlchannel. In this way, it becomes possible to improve coverage of acontrol channel through beamforming in an existing system.

In addition, a design of the beamformed control channel and thereference signal used for demodulating the beamformed control channel isused in this embodiment of the present disclosure, to improve coverageand performance of the control channel in comparison with a conventionalcontrol channel, and especially, to improve coverage of a cell using ahigh-frequency carrier. In addition, introduction of the beamformedcontrol channel has no impact on or has slight impact on compatibilityof a conventional terminal device.

Optionally, the first time-frequency resource includes a plurality ofresource element RE sets, each of the plurality of RE sets includes asame fixed quantity of REs, and the third time-frequency resourceincludes an RE at a preset location in each of the plurality of RE sets.

Optionally, the first time-frequency resource includes a plurality ofresource element RE sets, each of the plurality of RE sets includes asame fixed quantity of REs, and the third time-frequency resourceincludes all REs in at least one of the plurality of RE sets.

Optionally, the sending unit is further configured to: before thedetermining unit determines the first time-frequency resource, send anindication message to the terminal device. The indication messageindicates the preset rule.

Optionally, the determining unit is specifically configured to:

-   -   determine an aggregation level, where the aggregation level is        used to indicate a size of the candidate resource; and    -   select one candidate resource from a set of the plurality of        candidate resources corresponding to the aggregation level, and        use the candidate resource as the first time-frequency resource.

It should be understood that the network device 1000 shown in FIG. 10can implement processes related to the network device in the embodimentof FIG. 4. Operations and/or functions of modules of the network device1000 are respectively used for implementing corresponding processes inthe method embodiment of FIG. 4. For details, refer to the descriptionof the method embodiment. To avoid repetition, detailed description isproperly omitted herein.

Therefore, in this embodiment of the present disclosure, resourcescarrying the beamformed control channel and the reference signal of thebeamformed control channel are determined, to transmit the beamformedcontrol channel and the reference signal of the beamformed controlchannel. In this way, it becomes possible to improve coverage of acontrol channel through beamforming in an existing system.

FIG. 11 is a schematic block diagram of a terminal device 1100 fortransmitting a signal according to an embodiment of the presentdisclosure. As shown in FIG. 11, the terminal device 1100 includes:

-   -   a detection unit 1110, configured to detect a first        time-frequency resource, where the first time-frequency resource        is a first candidate resource in a plurality of candidate        resources;    -   an obtaining unit 1120, configured to obtain a second        time-frequency resource and a third time-frequency resource        based on the first time-frequency resource and a preset rule,        where the third time-frequency resource includes at least one        resource element RE at a predefined location in the first        time-frequency resource, the second time-frequency resource        includes a resource other than the third time-frequency resource        in the first time-frequency resource, the preset rule indicates        the predefined location, the second time-frequency resource is        used to carry a beamformed control channel, and the third        time-frequency resource is used to carry a reference signal of        the beamformed control channel; and    -   a demodulation unit 1130, configured to demodulate, based on the        reference signal that is of the beamformed control channel and        that is carried in the third time-frequency resource, the        beamformed control channel carried in the second time-frequency        resource.

Therefore, in this embodiment of the present disclosure, resourcescarrying the beamformed control channel and the reference signal of thebeamformed control channel are determined, to transmit the beamformedcontrol channel and the reference signal of the beamformed controlchannel. In this way, it becomes possible to improve coverage of acontrol channel through beamforming in an existing system.

Optionally, the first time-frequency resource includes a plurality ofresource element RE sets, each of the plurality of RE sets includes asame fixed quantity of REs, and the third time-frequency resourceincludes an RE at a preset location in each of the plurality of RE sets.

Optionally, the first time-frequency resource includes a plurality ofresource element RE sets, each of the plurality of RE sets includes asame fixed quantity of REs, and the third time-frequency resourceincludes all REs in at least one of the plurality of RE sets.

Optionally, the terminal device may further include:

-   -   a receiving unit, configured to: before the detection unit        detects the first time-frequency resource, receive an indication        message, where the indication message indicates the preset rule.

It should be understood that the terminal device 1100 shown in FIG. 11can implement processes related to the terminal device in the embodimentof FIG. 4. Operations and/or functions of modules of the terminal device1100 are respectively used for implementing corresponding processes inthe method embodiment of FIG. 4. For details, refer to the descriptionof the method embodiment. To avoid repetition, detailed description isproperly omitted herein.

Therefore, in this embodiment of the present disclosure, resourcescarrying the beamformed control channel and the reference signal of thebeamformed control channel are determined, to transmit the beamformedcontrol channel and the reference signal of the beamformed controlchannel. In this way, it becomes possible to improve coverage of acontrol channel through beamforming in an existing system.

FIG. 12 is a schematic block diagram of a network device 1200 fortransmitting a signal according to an embodiment of the presentdisclosure. As shown in FIG. 12, the network device 1200 includes:

-   -   a first determining unit 1210, configured to determine a first        time-frequency resource, where the first time-frequency resource        is a first candidate resource in a plurality of candidate        resources, and the first time-frequency resource is used to        carry a beamformed control channel;    -   a second determining unit 1220, configured to determine a second        time-frequency resource, where the second time-frequency        resource is a second candidate resource in the plurality of        candidate resources, or the second time-frequency resource is a        resource other than the plurality of candidate resources        configured for a terminal device, a third time-frequency        resource includes a time-frequency resource corresponding to a        reference signal of another control channel other than the        beamformed control channel, and the second time-frequency        resource is used to carry a reference signal of the beamformed        control channel; and    -   a sending unit 1230, configured to respectively transmit the        beamformed control channel and the reference signal of the        beamformed control channel to the terminal device by using the        first time-frequency resource and the second time-frequency        resource.

Therefore, in this embodiment of the present disclosure, resourcescarrying the beamformed control channel and the reference signal of thebeamformed control channel are determined, to transmit the beamformedcontrol channel and the reference signal of the beamformed controlchannel. In this way, it becomes possible to improve coverage of acontrol channel through beamforming in an existing system.

In addition, a design of the beamformed control channel and thereference signal used for demodulating the beamformed control channel isused in this embodiment of the present disclosure, to improve coverageand performance of the control channel in comparison with a conventionalcontrol channel, and especially, to improve coverage of a cell using ahigh-frequency carrier. In addition, introduction of the beamformedcontrol channel has no impact on or has slight impact on compatibilityof a conventional terminal device.

Optionally, when the second time-frequency resource is the secondcandidate resource in the plurality of candidate resources,

-   -   the second time-frequency resource is the second candidate        resource predefined in the plurality of candidate resources.

Optionally, when the second time-frequency resource is the secondcandidate resource in the plurality of candidate resources,

-   -   the second time-frequency resource is the second candidate        resource configured for the terminal device.

Optionally, when the second time-frequency resource is the resourceother than the plurality of candidate resources configured for theterminal device,

-   -   the second time-frequency resource includes a time-frequency        resource corresponding to another reference signal other than a        common reference signal (CRS), or the second time-frequency        resource includes a time-frequency resource corresponding to a        data channel.

Optionally, the sending unit is further configured to: before the seconddetermining unit determines the second time-frequency resource, send anindication message to the terminal device. The indication messageindicates a location of the second time-frequency resource.

Optionally, when the second time-frequency resource is the secondcandidate resource in the plurality of candidate resources, the seconddetermining unit is specifically configured to:

-   -   determine the second candidate time-frequency resource based on        a preset mapping relationship between the first time-frequency        resource and the second time-frequency resource.

Optionally, the second candidate time-frequency resource is one ofcandidate resources that have a same size as the first time-frequencyresource and that are in the plurality of candidate resources.

Optionally, the second candidate time-frequency resource is a candidateresource that is in candidate resources of a specified size in theplurality of candidate resources and that does not overlap with thefirst time-frequency resource.

Optionally, the first determining unit is specifically configured to:

-   -   determine an aggregation level, where the aggregation level is        used to indicate a size of the candidate resource; and    -   select one candidate resource from a set of the plurality of        candidate resources corresponding to the aggregation level, and        use the candidate resource as the first time-frequency resource.

It should be understood that the network device 1200 shown in FIG. 12can implement processes related to the network device in the embodimentof FIG. 8. Operations and/or functions of modules of the network device1200 are respectively used for implementing corresponding processes inthe method embodiment of FIG. 8. For details, refer to the descriptionof the method embodiment. To avoid repetition, detailed description isproperly omitted herein.

Therefore, in this embodiment of the present disclosure, resourcescarrying the beamformed control channel and the reference signal of thebeamformed control channel are determined, to transmit the beamformedcontrol channel and the reference signal of the beamformed controlchannel. In this way, it becomes possible to improve coverage of acontrol channel through beamforming in an existing system.

FIG. 13 is a schematic block diagram of a terminal device 1300 fortransmitting a signal according to an embodiment of the presentdisclosure. As shown in FIG. 13, the terminal device 1300 includes:

-   -   a first detection unit 1310, configured to detect a first        time-frequency resource, where the first time-frequency resource        is a first candidate resource in a plurality of candidate        resources, and the first time-frequency resource is used to        carry a beamformed control channel;    -   a second detection unit 1320, configured to detect a second        time-frequency resource, where the second time-frequency        resource is a second candidate resource in the plurality of        candidate resources, or the second time-frequency resource is a        resource other than the plurality of candidate resources        configured for the terminal device, and the second        time-frequency resource is used to carry a reference signal of        the beamformed control channel; and    -   a demodulation unit 1330, configured to demodulate, based on the        reference signal that is of the beamformed control channel and        that is carried in the second time-frequency resource, the        beamformed control channel carried in the first time-frequency        resource.

Therefore, in this embodiment of the present disclosure, resourcescarrying the beamformed control channel and the reference signal of thebeamformed control channel are determined, to transmit the beamformedcontrol channel and the reference signal of the beamformed controlchannel. In this way, it becomes possible to improve coverage of acontrol channel through beamforming in an existing system.

Optionally, when the second time-frequency resource is the secondcandidate resource in the plurality of candidate resources,

-   -   the second time-frequency resource is the second candidate        resource predefined in the plurality of candidate resources.

Optionally, when the second time-frequency resource is the secondcandidate resource in the plurality of candidate resources,

-   -   the second time-frequency resource is the second candidate        resource configured for the terminal device.

Optionally, when the second time-frequency resource is the resourceother than the plurality of candidate resources configured for theterminal device,

-   -   the second time-frequency resource includes a time-frequency        resource corresponding to another reference signal other than a        common reference signal (CRS), or the second time-frequency        resource includes a time-frequency resource corresponding to a        data channel.

Optionally, the terminal device further includes:

-   -   a receiving unit, configured to: before the second detection        unit detects the second time-frequency resource, receive an        indication message sent by the network device, where the        indication message indicates a location of the second        time-frequency resource.

Optionally, when the second time-frequency resource is the secondcandidate resource in the plurality of candidate resources,

-   -   the second time-frequency resource is the second candidate        resource determined based on a preset mapping relationship        between the first time-frequency resource and the second        time-frequency resource.

Optionally, the second candidate time-frequency resource is one ofcandidate resources that have a same size as the first time-frequencyresource and that are in the plurality of candidate resources.

Optionally, the second candidate time-frequency resource is a candidateresource that is in candidate resources of a specified size in theplurality of candidate resources and that does not overlap with thefirst time-frequency resource.

It should be understood that the terminal device 1300 shown in FIG. 13can implement processes related to the terminal device in the embodimentof FIG. 8. Operations and/or functions of modules of the terminal device1300 are respectively used for implementing corresponding processes inthe method embodiment of FIG. 8. For details, refer to the descriptionof the method embodiment. To avoid repetition, detailed description isproperly omitted herein.

Therefore, in this embodiment of the present disclosure, resourcescarrying the beamformed control channel and the reference signal of thebeamformed control channel are determined, to transmit the beamformedcontrol channel and the reference signal of the beamformed controlchannel. In this way, it becomes possible to improve coverage of acontrol channel through beamforming in an existing system.

FIG. 14 is a schematic block diagram of a network device 1400 fortransmitting a signal according to an embodiment of the presentdisclosure. As shown in FIG. 14, the network device 1400 includes aprocessor 1410 and a transceiver 1420. The processor 1410 is connectedto the transceiver 1420. Optionally, the network device 1400 furtherincludes a memory 1430. The memory 1430 is connected to the processor1410. Optionally, the apparatus 1400 further includes a bus system 1440.The processor 1410, the memory 1430, and the transceiver 1420 may beconnected by using the bus system 1440. The memory 1430 may beconfigured to store an instruction. The processor 1410 is configured toexecute the instruction stored in the memory 1430, to control thetransceiver 1420 to send information or a signal.

The processor 1410 is configured to: determine a first time-frequencyresource, where the first time-frequency resource is a first candidateresource in a plurality of candidate resources; and

-   -   obtain a second time-frequency resource and a third        time-frequency resource based on the first time-frequency        resource and a preset rule, where the third time-frequency        resource includes at least one resource element RE at a        predefined location in the first time-frequency resource, the        second time-frequency resource includes a resource other than        the third time-frequency resource in the first time-frequency        resource, the preset rule indicates the predefined location, the        second time-frequency resource is used to carry a beamformed        control channel, and the third time-frequency resource is used        to carry a reference signal of the beamformed control channel.

The transceiver 1420 is configured to respectively transmit thebeamformed control channel and the reference signal of the beamformedcontrol channel to a terminal device by using the second time-frequencyresource and the third time-frequency resource.

Therefore, in this embodiment of the present disclosure, resourcescarrying the beamformed control channel and the reference signal of thebeamformed control channel are determined, to transmit the beamformedcontrol channel and the reference signal of the beamformed controlchannel. In this way, it becomes possible to improve coverage of acontrol channel through beamforming in an existing system.

In addition, a design of the beamformed control channel and thereference signal used for demodulating the beamformed control channel isused in this embodiment of the present disclosure, to improve coverageand performance of the control channel in comparison with a conventionalcontrol channel, and especially, to improve coverage of a cell using ahigh-frequency carrier. In addition, introduction of the beamformedcontrol channel has no impact on or has slight impact on compatibilityof a conventional terminal device.

It should be understood that in this embodiment of the presentdisclosure, the processor 1410 may be a central processing unit (CPU),or the processor 1410 may be another general-purpose processor, adigital signal processor (DSP), an application-specific integratedcircuit (ASIC), a field programmable gate array (FPGA) or anotherprogrammable logic device, a discrete gate or a transistor logic device,a discrete hardware component, or the like. The general-purposeprocessor may be a microprocessor, or the processor may be anyconventional processor, or the like.

The memory 1430 may include a read-only memory and a random accessmemory, and provides an instruction and data for the processor 1410. Apart of the memory 1430 may further include a nonvolatile random accessmemory. For example, the memory 1430 may further store information abouta device type.

In addition to a data bus, the bus system 1440 may further include apower bus, a control bus, a status signal bus, and the like. However,for clarity of description, various buses are marked as the bus system1440 in the figure.

In an implementation process, the steps of the foregoing method may becompleted by using a hardware integrated logic circuit or an instructionin a software form in the processor 1410. The steps of the methoddisclosed with reference to the embodiments of the present disclosuremay be directly implemented by using a hardware processor, or may beimplemented by using a combination of a hardware module and a softwaremodule in the processor. The software module may be located in a maturestorage medium in the art such as a random memory, a flash memory, aread-only memory, a programmable read-only memory, an electricallyerasable programmable memory, or a register. The storage medium islocated in the memory 1430. The processor 1410 reads information fromthe memory 1430, and completes the steps of the foregoing method incombination with hardware of the processor 1410. To avoid repetition,details are not described herein.

Optionally, the first time-frequency resource includes a plurality ofresource element RE sets, each of the plurality of RE sets includes asame fixed quantity of REs, and the third time-frequency resourceincludes an RE at a preset location in each of the plurality of RE sets.

Optionally, the first time-frequency resource includes a plurality ofresource element RE sets, each of the plurality of RE sets includes asame fixed quantity of REs, and the third time-frequency resourceincludes all REs in at least one of the plurality of RE sets.

Optionally, the sending unit is further configured to: before thedetermining unit determines the first time-frequency resource, send anindication message to the terminal device. The indication messageindicates the preset rule.

Optionally, the processor 1410 is specifically configured to:

-   -   determine an aggregation level, where the aggregation level is        used to indicate a size of the candidate resource; and    -   select one candidate resource from a set of the plurality of        candidate resources corresponding to the aggregation level, and        use the candidate resource as the first time-frequency resource.

It should be understood that the network device 1400 shown in FIG. 14can implement processes related to the network device in the embodimentof FIG. 4. Operations and/or functions of modules of the network device1400 are respectively used for implementing corresponding processes inthe method embodiment of FIG. 4. For details, refer to the descriptionof the method embodiment. To avoid repetition, detailed description isproperly omitted herein.

Therefore, in this embodiment of the present disclosure, resourcescarrying the beamformed control channel and the reference signal of thebeamformed control channel are determined, to transmit the beamformedcontrol channel and the reference signal of the beamformed controlchannel. In this way, it becomes possible to improve coverage of acontrol channel through beamforming in an existing system.

FIG. 15 is a schematic block diagram of a network device 1500 fortransmitting a signal according to an embodiment of the presentdisclosure. As shown in FIG. 15, the network device 1500 includes aprocessor 1510 and a transceiver 1520. The processor 1510 is connectedto the transceiver 1520. Optionally, the network device 1500 furtherincludes a memory 1530. The memory 1530 is connected to the processor1510. Optionally, the apparatus 1500 further includes a bus system 1540.The processor 1510, the memory 1530, and the transceiver 1520 may beconnected by using the bus system 1540. The memory 1530 may beconfigured to store an instruction. The processor 1510 is configured toexecute the instruction stored in the memory 1530, to control thetransceiver 1520 to send information or a signal.

The processor 1510 is configured to: detect a first time-frequencyresource, where the first time-frequency resource is a first candidateresource in a plurality of candidate resources;

-   -   obtain a second time-frequency resource and a third        time-frequency resource based on the first time-frequency        resource and a preset rule, where the third time-frequency        resource includes at least one resource element RE at a        predefined location in the first time-frequency resource, the        second time-frequency resource includes a resource other than        the third time-frequency resource in the first time-frequency        resource, the preset rule indicates the predefined location, the        second time-frequency resource is used to carry a beamformed        control channel, and the third time-frequency resource is used        to carry a reference signal of the beamformed control channel;        and    -   demodulate, based on the reference signal that is of the        beamformed control channel and that is carried in the third        time-frequency resource, the beamformed control channel carried        in the second time-frequency resource.

Therefore, in this embodiment of the present disclosure, resourcescarrying the beamformed control channel and the reference signal of thebeamformed control channel are determined, to transmit the beamformedcontrol channel and the reference signal of the beamformed controlchannel. In this way, it becomes possible to improve coverage of acontrol channel through beamforming in an existing system.

In addition, a design of the beamformed control channel and thereference signal used for demodulating the beamformed control channel isused in this embodiment of the present disclosure, to improve coverageand performance of the control channel in comparison with a conventionalcontrol channel, and especially, to improve coverage of a cell using ahigh-frequency carrier. In addition, introduction of the beamformedcontrol channel has no impact on or has slight impact on compatibilityof a conventional terminal device.

It should be understood that in this embodiment of the presentdisclosure, the processor 1510 may be a central processing unit (CPU),or the processor 1510 may be another general-purpose processor, adigital signal processor (DSP), an application-specific integratedcircuit (ASIC), a field programmable gate array (FPGA) or anotherprogrammable logic device, a discrete gate or a transistor logic device,a discrete hardware component, or the like. The general-purposeprocessor may be a microprocessor, or the processor may be anyconventional processor, or the like.

The memory 1530 may include a read-only memory and a random accessmemory, and provides an instruction and data for the processor 1510. Apart of the memory 1530 may further include a nonvolatile random accessmemory. For example, the memory 1530 may further store information abouta device type.

In addition to a data bus, the bus system 1540 may further include apower bus, a control bus, a status signal bus, and the like. However,for clarity of description, various buses are marked as the bus system1540 in the figure.

In an implementation process, the steps of the foregoing method may becompleted by using a hardware integrated logic circuit or an instructionin a software form in the processor 1510. The steps of the methoddisclosed with reference to the embodiments of the present disclosuremay be directly implemented by using a hardware processor, or may beimplemented by using a combination of a hardware module and a softwaremodule in the processor. The software module may be located in a maturestorage medium in the art such as a random memory, a flash memory, aread-only memory, a programmable read-only memory, an electricallyerasable programmable memory, or a register. The storage medium islocated in the memory 1530. The processor 1510 reads information fromthe memory 1530, and completes the steps of the foregoing method incombination with hardware of the processor 1510. To avoid repetition,details are not described herein.

Optionally, the first time-frequency resource includes a plurality ofresource element RE sets, each of the plurality of RE sets includes asame fixed quantity of REs, and the third time-frequency resourceincludes an RE at a preset location in each of the plurality of RE sets.

Optionally, the first time-frequency resource includes a plurality ofresource element RE sets, each of the plurality of RE sets includes asame fixed quantity of REs, and the third time-frequency resourceincludes all REs in at least one of the plurality of RE sets.

Optionally, the transceiver 1520 is configured to: before the detectionunit detects the first time-frequency resource, receive an indicationmessage. The indication message indicates the preset rule.

It should be understood that the terminal device 1500 shown in FIG. 15can implement processes related to the terminal device in the embodimentof FIG. 4. Operations and/or functions of modules of the terminal device1500 are respectively used for implementing corresponding processes inthe method embodiment of FIG. 4. For details, refer to the descriptionof the method embodiment. To avoid repetition, detailed description isproperly omitted herein.

Therefore, in this embodiment of the present disclosure, resourcescarrying the beamformed control channel and the reference signal of thebeamformed control channel are determined, to transmit the beamformedcontrol channel and the reference signal of the beamformed controlchannel. In this way, it becomes possible to improve coverage of acontrol channel through beamforming in an existing system.

FIG. 16 is a schematic block diagram of a network device 1600 fortransmitting a signal according to an embodiment of the presentdisclosure. As shown in FIG. 16, the network device 1600 includes aprocessor 1610 and a transceiver 1620. The processor 1610 is connectedto the transceiver 1620. Optionally, the network device 1600 furtherincludes a memory 1630. The memory 1630 is connected to the processor1610. Optionally, the apparatus 1600 further includes a bus system 1640.The processor 1610, the memory 1630, and the transceiver 1620 may beconnected by using the bus system 1640. The memory 1630 may beconfigured to store an instruction. The processor 1610 is configured toexecute the instruction stored in the memory 1630, to control thetransceiver 1620 to send information or a signal.

The processor 1610 is configured to: determine a first time-frequencyresource, where the first time-frequency resource is a first candidateresource in a plurality of candidate resources, and the firsttime-frequency resource is used to carry a beamformed control channel;and

-   -   determine a second time-frequency resource, where the second        time-frequency resource is a second candidate resource in the        plurality of candidate resources, or the second time-frequency        resource is a resource other than the plurality of candidate        resources configured for a terminal device, and the second        time-frequency resource is used to carry a reference signal of        the beamformed control channel.

The transceiver 1620 is configured to respectively transmit thebeamformed control channel and the reference signal of the beamformedcontrol channel to the terminal device by using the secondtime-frequency resource and the third time-frequency resource.

Therefore, in this embodiment of the present disclosure, resourcescarrying the beamformed control channel and the reference signal of thebeamformed control channel are determined, to transmit the beamformedcontrol channel and the reference signal of the beamformed controlchannel. In this way, it becomes possible to improve coverage of acontrol channel through beamforming in an existing system.

In addition, a design of the beamformed control channel and thereference signal used for demodulating the beamformed control channel isused in this embodiment of the present disclosure, to improve coverageand performance of the control channel in comparison with a conventionalcontrol channel, and especially, to improve coverage of a cell using ahigh-frequency carrier. In addition, introduction of the beamformedcontrol channel has no impact on or has slight impact on compatibilityof a conventional terminal device.

It should be understood that in this embodiment of the presentdisclosure, the processor 1610 may be a central processing unit (CPU),or the processor 1610 may be another general-purpose processor, adigital signal processor (DSP), an application-specific integratedcircuit (ASIC), a field programmable gate array (FPGA) or anotherprogrammable logic device, a discrete gate or a transistor logic device,a discrete hardware component, or the like. The general-purposeprocessor may be a microprocessor, or the processor may be anyconventional processor, or the like.

The memory 1630 may include a read-only memory and a random accessmemory, and provides an instruction and data for the processor 1610. Apart of the memory 1630 may further include a nonvolatile random accessmemory. For example, the memory 1630 may further store information abouta device type.

In addition to a data bus, the bus system 1640 may further include apower bus, a control bus, a status signal bus, and the like. However,for clarity of description, various buses are marked as the bus system1640 in the figure.

In an implementation process, the steps of the foregoing method may becompleted by using a hardware integrated logic circuit or an instructionin a software form in the processor 1610. The steps of the methoddisclosed with reference to the embodiments of the present disclosuremay be directly implemented by using a hardware processor, or may beimplemented by using a combination of a hardware module and a softwaremodule in the processor. The software module may be located in a maturestorage medium in the art such as a random memory, a flash memory, aread-only memory, a programmable read-only memory, an electricallyerasable programmable memory, or a register. The storage medium islocated in the memory 1630. The processor 1610 reads information fromthe memory 1630, and completes the steps of the foregoing method incombination with hardware of the memory 1630. To avoid repetition,details are not described herein.

Optionally, when the second time-frequency resource is the secondcandidate resource in the plurality of candidate resources,

-   -   the second time-frequency resource is the second candidate        resource predefined in the plurality of candidate resources.

Optionally, when the second time-frequency resource is the secondcandidate resource in the plurality of candidate resources,

-   -   the second time-frequency resource is the second candidate        resource configured for the terminal device.

Optionally, when the second time-frequency resource is the resourceother than the plurality of candidate resources configured for theterminal device,

-   -   the second time-frequency resource includes a time-frequency        resource corresponding to another reference signal other than a        common reference signal (CRS), or the second time-frequency        resource includes a time-frequency resource corresponding to a        data channel.

Optionally, the sending unit is further configured to: before the seconddetermining unit determines the second time-frequency resource, send anindication message to the terminal device. The indication messageindicates a location of the second time-frequency resource.

Optionally, when the second time-frequency resource is the secondcandidate resource in the plurality of candidate resources, theprocessor 1610 is specifically configured to:

-   -   determine the second candidate time-frequency resource based on        a preset mapping relationship between the first time-frequency        resource and the second time-frequency resource.

Further, the second candidate time-frequency resource is one ofcandidate resources that have a same size as the first time-frequencyresource and that are in the plurality of candidate resources.

Alternatively, the second candidate time-frequency resource is acandidate resource that is in candidate resources of a specified size inthe plurality of candidate resources and that does not overlap with thefirst time-frequency resource.

Optionally, the processor 1610 is specifically configured to:

-   -   determine an aggregation level, where the aggregation level is        used to indicate a size of the candidate resource; and    -   select one candidate resource from a set of the plurality of        candidate resources corresponding to the aggregation level, and        use the candidate resource as the first time-frequency resource.

It should be understood that the network device 1600 shown in FIG. 16can implement processes related to the network device in the embodimentof FIG. 8. Operations and/or functions of modules of the network device1600 are respectively used for implementing corresponding processes inthe method embodiment of FIG. 8. For details, refer to the descriptionof the method embodiment. To avoid repetition, detailed description isproperly omitted herein.

Therefore, in this embodiment of the present disclosure, resourcescarrying the beamformed control channel and the reference signal of thebeamformed control channel are determined, to transmit the beamformedcontrol channel and the reference signal of the beamformed controlchannel. In this way, it becomes possible to improve coverage of acontrol channel through beamforming in an existing system.

FIG. 17 is a schematic block diagram of a network device 1700 fortransmitting a signal according to an embodiment of the presentdisclosure. As shown in FIG. 17, the network device 1700 includes aprocessor 1710 and a transceiver 1720. The processor 1710 is connectedto the transceiver 1720. Optionally, the network device 1700 furtherincludes a memory 1730. The memory 1730 is connected to the processor1710. Optionally, the apparatus 1700 further includes a bus system 1740.The processor 1710, the memory 1730, and the transceiver 1720 may beconnected by using the bus system 1740. The memory 1730 may beconfigured to store an instruction. The processor 1710 is configured toexecute the instruction stored in the memory 1730, to control thetransceiver 1720 to send information or a signal.

The processor 1710 is configured to: detect a first time-frequencyresource, where the first time-frequency resource is a first candidateresource in a plurality of candidate resources, and the firsttime-frequency resource is used to carry a beamformed control channel;

-   -   detect a second time-frequency resource, where the second        time-frequency resource is a second candidate resource in the        plurality of candidate resources, or the second time-frequency        resource is a resource other than the plurality of candidate        resources configured for a terminal device, and the second        time-frequency resource is used to carry a reference signal of        the beamformed control channel; and    -   demodulate, based on the reference signal that is of the        beamformed control channel and that is carried in the second        time-frequency resource, the beamformed control channel carried        in the first time-frequency resource.

Therefore, in this embodiment of the present disclosure, resourcescarrying the beamformed control channel and the reference signal of thebeamformed control channel are determined, to transmit the beamformedcontrol channel and the reference signal of the beamformed controlchannel. In this way, it becomes possible to improve coverage of acontrol channel through beamforming in an existing system.

In addition, a design of the beamformed control channel and thereference signal used for demodulating the beamformed control channel isused in this embodiment of the present disclosure, to improve coverageand performance of the control channel in comparison with a conventionalcontrol channel, and especially, to improve coverage of a cell using ahigh-frequency carrier. In addition, introduction of the beamformedcontrol channel has no impact on or has slight impact on compatibilityof a conventional terminal device.

It should be understood that in this embodiment of the presentdisclosure, the processor 1710 may be a central processing unit (CPU),or the processor 1710 may be another general-purpose processor, adigital signal processor (DSP), an application-specific integratedcircuit (ASIC), a field programmable gate array (FPGA) or anotherprogrammable logic device, a discrete gate or a transistor logic device,a discrete hardware component, or the like. The general-purposeprocessor may be a microprocessor, or the processor may be anyconventional processor, or the like.

The memory 1730 may include a read-only memory and a random accessmemory, and provides an instruction and data for the processor 1710. Apart of the memory 1730 may further include a nonvolatile random accessmemory. For example, the memory 1730 may further store information abouta device type.

In addition to a data bus, the bus system 1740 may further include apower bus, a control bus, a status signal bus, and the like. However,for clarity of description, various buses are marked as the bus system1740 in the figure.

In an implementation process, the steps of the foregoing method may becompleted by using a hardware integrated logic circuit or an instructionin a software form in the processor 1710. The steps of the methoddisclosed with reference to the embodiments of the present disclosuremay be directly implemented by using a hardware processor, or may beimplemented by using a combination of a hardware module and a softwaremodule in the processor. The software module may be located in a maturestorage medium in the art such as a random memory, a flash memory, aread-only memory, a programmable read-only memory, an electricallyerasable programmable memory, or a register. The storage medium islocated in the memory 1730. The processor 1710 reads information fromthe memory 1730, and completes the steps of the foregoing method incombination with hardware of the memory 1730. To avoid repetition,details are not described herein.

Optionally, when the second time-frequency resource is the secondcandidate resource in the plurality of candidate resources,

-   -   the second time-frequency resource is the second candidate        resource predefined in the plurality of candidate resources.

Optionally, when the second time-frequency resource is the secondcandidate resource in the plurality of candidate resources,

-   -   the second time-frequency resource is the second candidate        resource configured for the terminal device.

Optionally, when the second time-frequency resource is the resourceother than the plurality of candidate resources configured for theterminal device,

-   -   the second time-frequency resource includes a time-frequency        resource corresponding to another reference signal other than a        common reference signal (CRS), or the second time-frequency        resource includes a time-frequency resource corresponding to a        data channel.

Optionally, the transceiver 1720 is configured to: before the processor1710 detects the second time-frequency resource, receive an indicationmessage sent by the network device, where the indication messageindicates a location of the second time-frequency resource.

Optionally, when the second time-frequency resource is the secondcandidate resource in the plurality of candidate resources,

-   -   the second time-frequency resource is the second candidate        resource determined based on a preset mapping relationship        between the first time-frequency resource and the second        time-frequency resource.

Further, the second candidate time-frequency resource is one ofcandidate resources that have a same size as the first time-frequencyresource and that are in the plurality of candidate resources.

Alternatively, the second candidate time-frequency resource is acandidate resource that is in candidate resources of a specified size inthe plurality of candidate resources and that does not overlap with thefirst time-frequency resource.

It should be understood that the terminal device 1700 shown in FIG. 17can implement processes related to the terminal device in the embodimentof FIG. 8. Operations and/or functions of modules of the terminal device1700 are respectively used for implementing corresponding processes inthe method embodiment of FIG. 8. For details, refer to the descriptionof the method embodiment. To avoid repetition, detailed description isproperly omitted herein.

Therefore, in this embodiment of the present disclosure, resourcescarrying the beamformed control channel and the reference signal of thebeamformed control channel are determined, to transmit the beamformedcontrol channel and the reference signal of the beamformed controlchannel. In this way, it becomes possible to improve coverage of acontrol channel through beamforming in an existing system.

It should be understood that “one embodiment” or “an embodiment”mentioned in the whole specification means that particular features,structures, or characteristics related to the embodiment are included inat least one embodiment of the present disclosure. Therefore, “in oneembodiment” or “in an embodiment” appearing throughout thisspecification may be not necessarily a same embodiment. In addition,these particular features, structures, or characteristics may becombined in one or more embodiments in any appropriate manner. It shouldbe understood that sequence numbers of the foregoing processes do notmean execution sequences in various embodiments of the presentdisclosure. The execution sequences of the processes should bedetermined based on functions and internal logic of the processes, andshould not be construed as any limitation on the implementationprocesses of the embodiments of the present disclosure.

In addition, the terms “system” and “network” are interchangeable inthis specification. The term “and/or” in this specification describesonly an association relationship for describing associated objects andrepresents that three relationships may exist. For example, A and/or Bmay represent the following three cases: Only A exists, both A and Bexist, and only B exists. In addition, the character “/” in thisspecification generally indicates an “or” relationship between theassociated objects.

It should be understood that in the embodiments of the presentdisclosure, “B corresponding to A” indicates that B is associated withA, and B may be determined based on A. However, it should further beunderstood that determining B based on A does not mean that B isdetermined based on A only, to be specific, B may also be determinedbased on A and/or other information.

A person of ordinary skill in the art may be aware that, in combinationwith the examples described in the embodiments disclosed in thisspecification, units and algorithm steps may be implemented byelectronic hardware, computer software, or a combination thereof. Toclearly describe the interchangeability between the hardware and thesoftware, compositions and steps of each example are generally describedabove based on functions. Whether the functions are performed byhardware or software depends on particular applications and designconstraint conditions of the technical solutions. A person skilled inthe art may use different methods to implement the described functionsfor each particular application, but it should not be considered thatthe implementation goes beyond the scope of the present disclosure.

It may be clearly understood by a person skilled in the art that, forthe purpose of convenient and brief description, for a detailed workingprocess of the foregoing system, apparatus, and unit, refer to acorresponding process in the foregoing method embodiments, and detailsare not described herein again.

In the several embodiments provided in this application, it should beunderstood that the disclosed system, apparatus, and method may beimplemented in other manners. For example, the described apparatusembodiment is merely an example. For example, the unit division ismerely logical function division and may be other division in actualimplementation. For example, a plurality of units or components may becombined or integrated into another system, or some features may beignored or not performed. In addition, the displayed or discussed mutualcouplings or direct couplings or communications connections may beimplemented through some interfaces. The indirect couplings orcommunication connections between the apparatuses or units may beelectrical connections, mechanical connections, or connections in otherforms.

The units described as separate parts may or may not be physicallyseparate, and parts displayed as units may or may not be physical units,may be located in one position, or may be distributed on a plurality ofnetwork units. A part or all of the units may be selected based onactual requirements to achieve the objectives of the solutions of theembodiments of the present disclosure.

In addition, functional units in the embodiments of the presentdisclosure may be integrated into one processing unit, or each of theunits may exist alone physically, or two or more units are integratedinto one unit. The integrated unit may be implemented in a form ofhardware, or may be implemented in a form of a software functional unit.

From description of the foregoing implementations, a person skilled inthe art may clearly understand that the present disclosure may beimplemented by hardware, firmware or a combination thereof. When thepresent disclosure is implemented by software, the foregoing functionsmay be stored in a computer-readable medium or transmitted as one ormore instructions or code in the computer-readable medium. Thecomputer-readable medium includes a computer storage medium and acommunications medium. The communications medium includes any mediumthat enables a computer program to be transmitted from one place toanother. The storage medium may be any available medium accessible to acomputer. The following is used as an example but not a limitation: Thecomputer-readable medium may include a RAM, a ROM, an EEPROM, a CD-ROMor another optical disc storage, a disk storage medium or anothermagnetic storage device, or any other medium that can carry or storeexpected program code in a form of an instruction or a data structureand that can be accessed by a computer. In addition, any connection maybe appropriately defined as a computer-readable medium. For example, ifsoftware is transmitted from a website, a server, or another remotesource by using a coaxial cable, an optical fiber/cable, a twisted pair,a digital subscriber line (DSL), or wireless technologies such asinfrared ray, radio, and microwave, the coaxial cable, opticalfiber/cable, twisted pair, DSL, or wireless technologies such asinfrared ray, radio, and microwave are included in fixation of a mediumto which they belong. For example, a disk and disc used in the presentdisclosure includes a compact disc (CD), a laser disc, an optical disc,a digital versatile disc (DVD), a floppy disk, and a Blu-ray disc. Thedisk generally copies data by using a magnetic means, and the disccopies data optically by using a laser means. The foregoing combinationshould also be included in the protection scope of the computer-readablemedium.

In summary, the foregoing description is merely example embodiments ofthe technical solutions of the present disclosure, but is not intendedto limit the protection scope of the present disclosure. Anymodification, equivalent replacement, or improvement made withoutdeparting from the spirit and principle of the present disclosure shallfall within the protection scope of the present disclosure.

What is claimed is:
 1. A communication method, comprising: determining afirst time-frequency resource, wherein the first time-frequency resourceis a physical downlink control channel (PDCCH) candidate in a pluralityof PDCCH candidates; determining a second time-frequency resource and athird time-frequency resource in the first time-frequency resource,wherein the first time-frequency resource consists of a plurality ofresource element (RE) sets, all of the plurality of RE sets comprises asame fixed quantity of REs, and the third time-frequency resource islocated at a preset location in each of the plurality of RE sets,wherein each RE set comprises a plurality of RE groups (REGs), whereinthe third time-frequency resource includes at least one RE in each REGof the plurality of REGs in each RE set, and the second time-frequencyresource comprises a resource other than the third time-frequencyresource in the first time-frequency resource, the second time-frequencyresource is used to carry a beamformed control channel, and the thirdtime-frequency resource is used to carry a reference signal of thebeamformed control channel; and transmitting the beamformed controlchannel and the reference signal of the beamformed control channel to aterminal device by using the second time-frequency resource and thethird time-frequency resource.
 2. The method according to claim 1,wherein the first time-frequency resource is associated with one or morecontrol resource elements (CCEs), and a number of the one or more CCEsis equal to an aggregation level.
 3. The method according to claim 1,wherein the determining, the first time-frequency resource comprises:determining an aggregation level, wherein the aggregation level isassociated with the PDCCH candidate; and determining the firsttime-frequency resource according to the aggregation level.
 4. Themethod according to claim 1, wherein the second time-frequency resourceand the third time-frequency resource are determined according to afirst rule, and the first rule indicates the preset location.
 5. Acommunication device, comprising: a storage medium including executableinstructions; and a processor; wherein the executable instructions, whenexecuted by the processor, cause the device to: determine a firsttime-frequency resource, wherein the first time-frequency resource is aphysical downlink control channel (PDCCH) candidate in a plurality ofPDCCH candidates; determine a second time-frequency resource and a thirdtime-frequency resource in the first time-frequency resource, whereinthe first time-frequency resource consists of a plurality of resourceelement (RE) sets, all of the plurality of RE sets comprises a samefixed quantity of REs, and the third time-frequency resource is locatedat a preset location in each of the plurality of RE sets, wherein eachRE set comprises a plurality of RE groups (REGs), wherein the thirdtime-frequency resource includes at least one RE in each REG of theplurality of REGs in each RE set, and the second time-frequency resourcecomprises a resource other than the third time-frequency resource in thefirst time-frequency resource, the second time-frequency resource isused to carry a beamformed control channel, and the third time-frequencyresource is used to carry a reference signal of the beamformed controlchannel; and transmit the beamformed control channel and the referencesignal of the beamformed control channel to a terminal device by usingthe second time-frequency resource and the third time-frequencyresource.
 6. The device according to claim 5, wherein the firsttime-frequency resource is associated with one or more control resourceelements (CCEs), and a number of the one or more CCEs is equal to anaggregation level.
 7. The method according to claim 5, wherein thedetermine the first time-frequency resource comprises: determine anaggregation level, wherein the aggregation level is associated with thePDCCH candidate; and determine the first time-frequency resourceaccording to the aggregation level.
 8. The method according to claim 5,wherein the second time-frequency resource and the third time-frequencyresource are determined according to a first rule, and the first ruleindicates the preset location.
 9. A non-transitory computer-readablemedium, wherein the non-transitory computer-readable medium storesinstructions that, when executed by a processor, cause the processor to:determine a first time-frequency resource, wherein the firsttime-frequency resource is a physical downlink control channel (PDCCH)candidate in a plurality of PDCCH candidates; determine a secondtime-frequency resource and a third time-frequency resource in the firsttime-frequency resource, wherein the first time-frequency resourceconsists of a plurality of resource element (RE) sets, all of theplurality of RE sets comprises a same fixed quantity of REs, and thethird time-frequency resource is located at a preset location in each ofthe plurality of RE sets, wherein each RE set comprises a plurality ofRE groups (REGs), wherein the third time-frequency resource includes atleast one RE in each REG of the plurality of REGs in each RE set, andthe second time-frequency resource comprises a resource other than thethird time-frequency resource in the first time-frequency resource, thesecond time-frequency resource is used to carry a beamformed controlchannel, and the third time-frequency resource is used to carry areference signal of the beamformed control channel; and transmit thecontrol channel by using the second time-frequency resource and thereference signal by using the third time-frequency resource.
 10. Thenon-transitory computer-readable medium according to claim 9, whereinthe first time-frequency resource is associated with one or more controlresource elements (CCEs), and a number of the one or more CCEs is equalto an aggregation level.
 11. The non-transitory computer-readable mediumaccording to claim 9, wherein the determine the first time-frequencyresource comprises: determine an aggregation level, wherein theaggregation level is associated with the PDCCH candidate; and determinethe first time-frequency resource according to the aggregation level.12. The non-transitory computer-readable medium according to claim 9,wherein the second time-frequency resource and the third time-frequencyresource are determined according to a first rule, and the first ruleindicates the preset location.